Duplex stainless steel ER2594 welding material and preparation method thereof

Abstract

The invention relates to a duplex stainless steel ER2594 welding material and a preparation method thereof, and the welding material is prepared from the following raw materials in percentage by weight: less than or equal to 0.018% of C; 0.50% to 0.60% of Si; 0.60% to 0.80% of Mn; less than or equal to 0.020% of P; s: < = 0.002%; ni: 8.55 to 8.70%; cr: 25.80% to 25.95%; 3.80% to 3.90% of Mo; 0.22% to 0.24% of N; cu: less than or equal to 0.3%; b: 0.0015% to 0.0030% of the total weight of the raw The balance is iron and inevitable impurities; the preparation method comprises the steps that low-P, low-Pb, low-Sn, low-As, low-Sb and low-Bi waste stainless steel is selected, the waste stainless steel is sequentially subjected to smelting, die casting, two-fire cogging and blank solid solution, intermediate billet coping and cogging, intermediate billet rolling and wire rod surface treatment, and the welding material is obtained. The comprehensive performance of the welding material is improved, a wire product without surface defects and core precipitation can be produced in a high-speed wire continuous rolling unit, the yield can reach 85% or above, the surface of an intermediate blank is free of precipitation, it is guaranteed that cracking caused by grinding is avoided in the grinding process, and remarkable economic benefits and environmental protection benefits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of steel manufacturing, and in particular to a duplex stainless steel ER2594 welding material and a preparation method thereof. Background Art

[0002] The microstructure of duplex stainless steel is a mixture of austenite and ferrite, with a ratio of about 45-55%. This material is widely used in pulp and paper, shipping, petrochemical, and natural gas industries due to its excellent corrosion resistance, outstanding mechanical properties, and good weldability. However, due to the differences in crystal structure and properties between austenite and ferrite, the plastic deformation behavior of duplex stainless steel is more complex than that of single-phase ferrite and austenitic stainless steel. Although the composition design of duplex stainless steel welding materials strives to be consistent with that of the base material, considering the burnout of alloying elements during welding, its alloy content is usually higher than that of conventional base materials. For example, according to AWS A5.9-2017 "Stainless Steel Electrodes and Rods Specification", the composition requirements of welding materials include: carbon (C) ≤ 0.03%, silicon (Si) ≤ 1.00%, manganese (Mn) ≤ 2.5%, phosphorus (P) ≤ 0.03%, sulfur (S) ≤ 0.020%, nickel (Ni) 8.00~10.50%, chromium (Cr) 24.00~27.00%, molybdenum (Mo) 2.50~4.50%, nitrogen (N) 0.20~0.30%, copper (Cu) ≤ 1.50%, and the rest is iron (Fe) and unavoidable impurities. This composition design also leads to some rolling problems during hot forming.

[0003] The Chinese patent with publication number CN117120649A discloses a duplex stainless steel welded joint, which has a base material and a weld metal, wherein the weld metal is C: 0.001%~0.030%, Si: 0.05%~0.70%, Mn: 0.05%~0.85%, P: less than 0.030%, S: less than 0.0030%, Cr: 21.00%~28.00%, Ni: 5.00%~1 1.00%, Mo: 2.00%~4.50%, Cu: 0.01~4.00%, Sol.Al: 0.0010~0.0500%, N: 0.080%~0.400%, B: 0.0001~0.0100% and the balance Fe and impurities. The duplex stainless steel welded joint satisfies the contents of each element in the base material and the weld metal and satisfies the formula (1) and formula (2), Si+3Mn≤3.00 (1), 0<BH / BW<0.15 (2), where the content of the corresponding element in the weld metal is substituted in mass % at the symbol of each element in the formula (1), where BH in the formula (2) is substituted for the Cap height (mm) of the weld metal, and BW is substituted for the Cap width (mm) of the weld metal.

[0004] The above-mentioned prior art solutions have the following defects: by satisfying formula (1) and formula (2), the above-mentioned stainless steel welded joint can effectively suppress the undercut phenomenon and improve the fatigue characteristics, thereby achieving excellent weldability; however, at the hot working deformation temperature, due to the difference in strength and plasticity of the two metallographic structures in the duplex stainless steel and the difference in their deformation behaviors, the thermoplasticity will be reduced; this decrease in thermoplasticity will lead to the deterioration of the hot working performance of the duplex stainless steel and the increase in high temperature deformation resistance; therefore, during the hot working process, problems such as hot deformation cracking, the formation of heat treatment pits and oxide scales, and increased difficulty in hot working may occur, which will directly affect the yield rate of the welding material.

[0005] The Chinese patent with publication number CN116967652A discloses a duplex stainless steel welding wire and a preparation method thereof, wherein the duplex stainless steel welding wire comprises the following elements, expressed in weight percentage as follows: C: 0.01-0.04%, Si: 0.5-1.5%, Mn: 0.8-3.2%, Cr: 24.0-30.0%, Ni: 8.0-13.0%, Mo: 2.0-6.0%, Cu: 1.0-2.5%, N: 0.1-0.4% , P≤0.025%, S≤0.005%, O≤0.003%, B: 0.010~0.030%, and the balance Fe; the preparation method comprises the following steps: S100: smelting according to the weight percentage of the elements of the duplex stainless steel welding wire to obtain the alloy solution of the duplex stainless steel welding wire; S200: continuously casting, cutting, hot-rolling wire rods, and drawing the alloy solution of the duplex stainless steel welding wire in step S100 to obtain the duplex stainless steel welding wire.

[0006] The above-mentioned prior art solutions have the following defects: the above-mentioned method involves directly preparing continuous casting billets from alloy solution through continuous casting, followed by hot rolling and drawing; however, due to the easy occurrence of defects in duplex stainless steel during hot working, coupled with abnormalities in continuous casting production equipment, this may lead to unsustainable production, and these problems include cracking and scrapping of duplex welding material steel ingots due to surface defects when billeting into intermediate billets, cracking of intermediate billets during grinding, and cracking and steel piling of welding materials during continuous rolling, all of which may affect the yield rate of welding materials. Summary of the invention

[0007] In view of the shortcomings of the prior art, the first object of the present invention is to provide a duplex stainless steel ER2594 welding material, which solves the problems of poor hot working performance and high resistance to high temperature deformation of the existing ER2594, and has the advantages of improving the tensile strength, elongation after fracture, cross-sectional shrinkage and corrosion resistance of the welding material.

[0008] The second object of the present invention is to provide a method for preparing duplex stainless steel ER2594 welding material, which solves the problems of cracking of duplex welding material steel ingot when blanking into intermediate blanks, cracking of intermediate blanks during grinding, and cracking and steel piling of welding materials during continuous rolling, and has the advantage of improving the welding material yield rate.

[0009] To achieve the above first object, the present invention provides the following technical solutions: A duplex stainless steel ER2594 welding material is made of the following raw materials in weight percentage: C: ≤0.018%; Si: 0.50~0.60%; Mn: 0.60~0.80%; P: ≤0.020%; S: ≤0.002%; Ni: 8.55~8.70%; Cr: 25.80~25.95%; Mo: 3.80~3.90%; N: 0.22~0.24%; Cu: ≤0.3%; B: 0.0015~0.0030%; The balance is iron and unavoidable impurities.

[0010] By adopting the above technical solution, carbon (C): carbon is an austenite forming element, and increasing its content can significantly increase the strength of stainless steel. When the carbon content is too high, the welding performance of stainless steel will be greatly reduced. The carbon content of the present invention is controlled to be: ≤0.018%; Silicon (Si): Silicon is a strong deoxidizer, which reduces the oxygen content in steel and improves inclusions in steel; however, higher silicon content will also reduce the cold working performance of stainless steel. It effectively improves the fluidity of the molten pool and reduces the oxidizing elements in the molten pool during welding; therefore, the silicon content of the present invention is controlled at 0.5-0.6%; Phosphorus (P): Phosphorus is a harmful element in steel, which can make steel cold and brittle. At the same time, P will cause welding cracks after welding. The phosphorus content of the present invention is controlled to: ≤0.02%; Sulfur (S): Sulfur is a harmful element for ordinary stainless steel, but too high sulfur will cause sulfides to deform along the rolling direction, forming long strips and gathering together, seriously affecting the plasticity of stainless steel. During the welding process, sulfides will be suspended in the upper layer of the molten pool with the input of heat and have strong activity, improving the fluidity of the molten pool. Therefore, the sulfur content of the present invention is controlled to: ≤0.002%; Nickel (Ni): Ni is a strong austenite-forming element, which keeps the stainless steel in a stable austenite state, improves the strength and plasticity of the material, and the combination of nickel and Cr can also significantly improve the corrosion resistance of the stainless steel. Therefore, the nickel content of the present invention is controlled at 8.55-8.70%; Chromium (Cr): Chromium is the main element in stainless steel. When the chromium content of the steel exceeds 10.5, a passivation film will be formed on the surface, which will hinder the further occurrence of oxidation reaction, so that the stainless steel has significant corrosion resistance. As the chromium content in stainless steel increases, the pitting points of stainless steel increase and the corrosion resistance improves. Therefore, the chromium content of the present invention is controlled at 25.80-25.95%; Boron (B): Adding B element to austenitic stainless steel can significantly improve the grain boundary strength of austenitic stainless steel and improve the high-temperature plasticity of the material. Experimental studies have shown that for nitrogen-containing austenite with poor hot working performance, adding a certain amount of B element can increase the cross-sectional shrinkage of the material by 10~15% at 900~1000℃; for this reason, microalloying of boron element is usually an important means to improve the hot working performance of austenitic stainless steel; but the content of B element cannot be too high, otherwise it will cause grain boundary segregation and bring harmful effects. For this reason, we control the B content at 15~35ppm.

[0011] Furthermore, the welding material is made of the following raw materials in percentage by weight: C: 0.005, 0.006, 0.007, 0.008, 0.009, 0.010, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017 or 0.018%; Si: 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59 or 0.60%; Mn: 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79 or 0.80%; P: 0.005, 0.006, 0.007, 0.008, 0.009, 0.010, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, or 0.020%; S: 0.0005, 0.0006, 0.0007, 0.0008, 0.0009, 0.0010, 0.0011, 0.0012, 0.0013, 0.0014, 0.0015, 0.0016, 0.0017, 0.0018, 0.0019 or 0.0020%; Ni: 8.55, 8.56, 8.57, 8.58, 8.59, 8.60, 8.61, 8.62, 8.63, 8.64, 8.65, 8.66, 8.67, 8.68, 8.69 or 8.70%; Cr: 25.80, 25.81, 25.82, 25.83, 25.84, 25.85, 25.86, 25.87, 25.88, 25.89, 25.90, 25.91, 25.92, 25.93, 25.94 or 25.95%; Mo: 3.80, 3.81, 3.82, 3.83, 3.84, 3.85, 3.86, 3.87, 3.88, 3.89 or 3.90%; N: 0.220, 0.221, 0.222, 0.223, 0.224, 0.225, 0.226, 0.227, 0.228, 0.229, 0.230, 0.231, 0.232, 0.233, 0.234, 0.235, 0.236, 0.237, 0.238, 0.239 or 0.240%; Cu: 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29 or 0.3%; B: 0.0015, 0.0016, 0.0017, 0.0018, 0.0019, 0.0020, 0.0021, 0.0022, 0.0023, 0.0024, 0.0025, 0.0026, 0.0027, 0.0028, 0.0029 or 0.0030%; The balance is iron and unavoidable impurities.

[0012] Furthermore, the welding material satisfies the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0013] The present invention is based on the composition requirements in the standard AWS A5.9-2017 "Stainless Steel Welding Rod and Welding Rod Specification", in order to improve the poor hot working performance and high temperature deformation resistance of ER2594, the composition is optimized, and the preferred composition complies with three requirements: 1. The DFW value calculated according to WRC-1992 is controlled to be 26~29; 2. The crack defect sensitivity coefficient CSI value is controlled within 10.5; 3. The elements that have a greater impact on welding performance, such as C, P components, and the five harmful elements such as As, Sn, Sb, Pb, and Bi, are as low as possible. By controlling the DFW value, CSI value, and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance is reduced during the hot working process, and cracking is reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly improved, and the high temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate, and suitable for mass production.

[0014] To achieve the above second purpose, the present invention provides the following technical solutions: A preparation method of duplex stainless steel ER2594 welding material, comprising the steps of selecting waste stainless steel with low P, low Pb, low Sn, low As, low Sb and low Bi, and sequentially smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling and wire rod surface treatment on the waste stainless steel to obtain the welding material.

[0015] Furthermore, in the smelting process, the scrap stainless steel is first smelted by a 30t electric arc furnace to control the P content in the remaining molten steel to be ≤0.020% to obtain crude molten steel, and then decarburization smelting and deoxidation smelting are completed in sequence by an AOD furnace to remove most of the impurities in the molten steel, and the C content in the crude molten steel is controlled to be ≤0.018%, and the oxygen activity reaches 10-60ppm, and then it is refined by an LF furnace, alloys are added according to the content of each element in the raw material, and the tapping temperature is adjusted to obtain smelted molten steel.

[0016] Furthermore, in the process of the mold casting, the molten steel obtained by smelting is poured into the ingot mold, and the superheat temperature of the molten steel is controlled to be 50-80°C. During the pouring, it is noted that the molten steel does not roll up slag, and the riser shrinkage compensation time should be controlled to be 3-5 minutes. The flow is gradually reduced and the thin flow is filled, and the ingot blank is obtained by condensation.

[0017] Furthermore, in the process of two-fire blanking and blank solid solution, the steel ingot blank obtained by die casting is first heated by a chamber regenerative furnace, and is heated and kept warm for 50-70 minutes at a low temperature stage of 550-650°C, heated to a high temperature stage of 900-1100°C, heated and kept warm for 80-100 minutes, heated to a steel-tapping temperature stage of 1200-1350°C, heated and kept warm for 100-150 minutes. After steel-tapping, the 14-inch steel ingot blank is blanked to a 280mm*300mm intermediate blank by an 850 blanking reciprocating rolling mill, and is further heated by a chamber regenerative furnace, heated to a blank solid solution stage of 1200-1350°C, heated and kept warm for 50-70 minutes. The intermediate blank is cooled in stages, and a circulating water tank is used, and the water entry time is controlled at 50-60 seconds each time until the surface temperature drops below 150°C.

[0018] Furthermore, in the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is first ground with a 30-mesh grinding wheel of a grinding wheel grinder to remove some crack defects on the surface of the intermediate billet, and then continued to be heated by a chamber heat storage furnace, the temperature is raised to 1200~1350℃ in the steel-out temperature stage, and the heating and heat preservation are carried out for 100~150min, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire.

[0019] Furthermore, during the rolling of the intermediate billet, the intermediate billet obtained by grinding and opening the intermediate billet is first heated by a walking-beam heating furnace, and is heated and kept warm for 80 to 120 minutes at a low temperature stage of 900 to 1100°C, and is heated to a high temperature stage of 1280 to 1300°C, and is heated for 30 to 60 minutes, and then is rolled out of the furnace, wherein the rough rolling adopts dry head rolling, and the rolling process uses induction heating to heat the rolled piece again, and the temperature is set at 1100 to 1200°C, and the temperature of the rolled piece is controlled to be ≥1000°C during the entire rolling process, and then it is processed by a laying head and a water explosion treatment equipment in sequence, and the temperature of the rolled wire rod obtained by rolling is sharply reduced to below 300°C, so as to reduce the precipitation caused by the cooling time of the wire rod.

[0020] Furthermore, in the process of the wire rod surface treatment, the wire rod obtained by rolling the intermediate billet is first pickled in a pickling solution for 30-60 minutes, and the temperature of the pickling solution is controlled to be 40-60° C., and then passivation, neutralization, and drying treatments are performed in sequence to obtain the welding material.

[0021] Furthermore, in the process of the wire rod surface treatment, the pickling solution is made of the following raw materials in percentage by weight: Sulfuric acid 12~20%; Hydrochloric acid 9~16%; Hydrofluoric acid 3~5%; The balance is water.

[0022] In summary, the beneficial technical effects of the present invention are: 1. By precisely controlling the element content in the raw materials and the key parameters in the smelting process, duplex stainless steel ER2594 welding materials with excellent performance can be produced. This welding material not only has a high ferrite content, but also has a low deformation resistance during hot working, thereby effectively reducing the risk of cracking; in addition, by adding boron, the grain boundary strength of austenitic stainless steel is significantly improved, and the high-temperature plasticity of the material is improved, so that the welding material can still maintain good processing performance in a high-temperature environment; 2. The preparation method of the present invention simplifies the production process, is easy to operate, and is suitable for mass production; by using waste stainless steel with low harmful elements as raw materials, not only the production cost is reduced, but also environmental pollution is reduced; the combination of electric arc furnace, AOD furnace and LF furnace used in the smelting process ensures the purity of molten steel and the uniformity of composition, thereby ensuring the high quality of welding materials; 3. In the key production links such as die casting, billeting, solution treatment and rolling, the internal quality of ingots and intermediate billets is ensured by precisely controlling temperature and time, avoiding defects such as cracks and inclusions. In particular, in the intermediate billet rolling process, the dry rolling and induction heating technologies are used to effectively improve the rolling efficiency and product quality. 4. During the wire rod surface treatment process, the precise control of the pickling solution ratio and treatment time ensures the cleanliness and passivation effect of the welding material surface, thereby improving the corrosion resistance and welding performance of the welding material; through the steps of pickling, passivation, neutralization and drying, a uniform protective film is formed on the surface of the welding material, which effectively prevents rust and pollution; 5. The duplex stainless steel ER2594 welding material and preparation method thereof provided by the present invention not only improve the comprehensive performance of the welding material, but also can realize the production of wire products with no surface defects and no precipitation in the core in a high-speed continuous rolling mill, and the yield rate can reach more than 85%, and simplifies the production process, reduces the production cost, can realize large-scale production, and there is no precipitation on the surface of the intermediate billet, ensuring that there is no cracking caused by grinding during the grinding process, and has significant economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an appearance inspection picture of the wire intermediate billet produced by S3 in Example 1 of the present invention.

[0024] Figure 2 This is an appearance inspection picture of the wire intermediate billet prepared by S3 in Comparative Example 2 of the present invention.

[0025] Figure 3 This is an appearance inspection diagram of the wire intermediate billet before S4 grinding and solutionizing in Example 1 of the present invention.

[0026] Figure 4 This is an appearance inspection diagram of the wire intermediate billet after S4 grinding and solutionizing in Example 1 of the present invention.

[0027] Figure 5 It is a schematic structural diagram of the water explosion treatment equipment of S5 in Example 1 of the present invention.

[0028] Figure 6 It is the metallographic structure diagram of the wire rod obtained by S5 rolling in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] In order to make the technical means, creative features, objectives and functions achieved by the present invention clearer and easier to understand, the present invention is further explained below in conjunction with the accompanying drawings and specific implementation methods.

[0031] Example 1: A duplex stainless steel ER2594 welding material disclosed in the present invention is made of the following raw materials in percentage by weight: C: 0.016%; Si: 0.53%; Mn: 0.72%; P: 0.0152%; S: 0.002%; Ni: 8.57; Cr: 25.85%; Mo: 3.88%; N: 0.226%; Cu: 0.08%; B: 0.0015%; The balance is iron and unavoidable impurities.

[0032] The welding material shall satisfy the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0033] By controlling the DFW value, CSI value and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance and cracking during hot working are reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly increased, and the high-temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate and suitable for mass production.

[0034] In addition, the present invention also discloses a preparation method of duplex stainless steel ER2594 welding material, which selects waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%), and sequentially performs smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment on the waste stainless steel to obtain the welding material, and the specific implementation method is as follows: S1 first smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then passes through an AOD furnace to complete decarburization smelting and deoxidation smelting in sequence, removes most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 50ppm, and then passes through an LF furnace for refining, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2 pours the molten steel obtained by smelting into the ingot mold, controls the superheat temperature of the molten steel to 58°C (casting temperature 1504°C), pays attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 4 minutes, gradually reduces the flow, fills with thin flow, and condenses to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 600°C in the low temperature stage for 60 minutes, heats and holds the temperature at 1000°C in the high temperature stage for 90 minutes, heats and holds the temperature at 1280°C in the steel tapping temperature stage for 120 minutes. After steel tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats and holds the temperature at 1280°C in the solid solution stage of the billet for 60 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used. The water entry time is controlled at 55s each time, until the surface temperature drops below 150°C. S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground with a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1280℃ at the tapping temperature stage, heated and kept warm for 120 minutes, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 firstly heats the intermediate billet obtained by grinding and opening the intermediate billet through a step-beam heating furnace, and sequentially heats and holds the temperature at 1000°C in the low temperature stage for 90 minutes, heats to 1280°C in the high temperature stage for 45 minutes, and then goes through furnace rolling. In which, the rough rolling adopts dry head rolling, and the rolling process uses induction heating to heat the rolled piece again. The rolling temperature is set at 1200°C, and the temperature of the rolled piece is controlled at 1089°C during the entire rolling process. Then, it is sequentially processed by a laying head and a water explosion treatment equipment to sharply reduce the temperature of the rolled wire rod to below 300°C, so as to reduce the precipitation caused by the cooling time of the wire rod; S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 48 minutes, and the temperature of the pickling solution is controlled at 54°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0035] Example 2: A duplex stainless steel ER2594 welding material disclosed in the present invention is made of the following raw materials in percentage by weight: C: 0.018%; Si: 0.60%; Mn: 0.80%; P: 0.020%; S: 0.018%; Ni: 8.70; Cr: 25.95%; Mo: 3.90%; N: 0.240%; Cu: 0.30%; B: 0.0030%; The balance is iron and unavoidable impurities.

[0036] The welding material shall satisfy the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0037] By controlling the DFW value, CSI value and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance and cracking during hot working are reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly increased, and the high-temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate and suitable for mass production.

[0038] In addition, the present invention also discloses a preparation method of duplex stainless steel ER2594 welding material, which selects waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%), and sequentially performs smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment on the waste stainless steel to obtain the welding material, and the specific implementation method is as follows: S1 firstly smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then sequentially completes decarburization smelting and deoxidation smelting through an AOD furnace to remove most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 10ppm, and then refines through an LF furnace, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2 pours the molten steel obtained by smelting into the ingot mold, controls the superheat temperature of the molten steel to 80°C (casting temperature 1526°C), pays attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 5 minutes, gradually reduces the flow, fills with thin flow, and condenses to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 650°C in the low temperature stage for 70 minutes, heats to 1100°C in the high temperature stage for 100 minutes, heats to 1350°C in the tapping temperature stage for 150 minutes, and then, after tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats to 1350°C in the solid solution stage of the billet, and heats and holds the temperature for 70 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used, and the water entry time is controlled at 60s each time, until the surface temperature drops below 150°C; S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground by a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1350℃ at the tapping temperature stage, heated and kept warm for 150min, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 first heats the intermediate billet obtained by grinding and opening the intermediate billet through a step-beam heating furnace, and then heats and holds the temperature at 1100°C in the low temperature stage for 100 minutes, heats to 1300°C in the high temperature stage for 60 minutes, and then goes through furnace rolling. In the rough rolling, dry rolling is adopted. In the rolling process, induction heating is used to heat the rolled piece again. The rolling temperature is set at 1200°C, and the temperature of the rolled piece is controlled at 1000°C during the entire rolling process. Then, the rolled piece is processed by a laying head and a water explosion treatment device in sequence, and the temperature of the rolled wire rod is sharply reduced to below 300°C to reduce the precipitation caused by the cooling time of the wire rod. S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 60 minutes, and the temperature of the pickling solution is controlled at 60°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0039] Example 3: A duplex stainless steel ER2594 welding material disclosed in the present invention is made of the following raw materials in percentage by weight: C: 0.017%; Si: 0.58%; Mn: 0.78%; P: 0.018%; S: 0.016%; Ni: 8.68; Cr: 25.93%; Mo: 3.88%; N: 0.238%; Cu: 0.25%; B: 0.0028%; The balance is iron and unavoidable impurities.

[0040] The welding material shall satisfy the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0041] By controlling the DFW value, CSI value and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance and cracking during hot working are reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly increased, and the high-temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate and suitable for mass production.

[0042] In addition, the present invention also discloses a preparation method of duplex stainless steel ER2594 welding material, which selects waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%), and sequentially performs smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment on the waste stainless steel to obtain the welding material, and the specific implementation method is as follows: S1 first smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then passes through an AOD furnace to complete decarburization smelting and deoxidation smelting in sequence, removes most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 15ppm, and then passes through an LF furnace for refining, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2: pour the molten steel obtained by smelting into the ingot mold, control the superheat temperature of the molten steel to 75°C (casting temperature 1521°C), pay attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 5 minutes, gradually reduce the flow, fill with thin flow, and condense to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 630°C in the low temperature stage for 68 minutes, heats and holds the temperature at 1080°C in the high temperature stage for 98 minutes, heats and holds the temperature at 1320°C in the tapping temperature stage for 140 minutes. After tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats and holds the temperature at 1320°C in the solid solution stage of the billet for 68 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used. The water entry time is controlled at 58s each time, until the surface temperature drops below 150°C. S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground by a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1320℃ at the tapping temperature stage, heated and kept warm for 140 minutes, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 first heats the intermediate billet obtained by grinding and opening the intermediate billet through a step-beam heating furnace, and then heats and holds the temperature at 1080°C in the low temperature stage for 98 minutes, heats to 1280°C in the high temperature stage for 55 minutes, and then goes through furnace rolling. In the rough rolling, dry rolling is adopted. In the rolling process, induction heating is used to heat the rolled piece again. The rolling temperature is set at 1180°C, and the temperature of the rolled piece is controlled at 1050°C during the entire rolling process. Then, the rolled piece is processed by a laying head and a water explosion treatment device in sequence, and the temperature of the rolled wire rod is sharply reduced to below 300°C to reduce the precipitation caused by the cooling time of the wire rod. S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 55 minutes, and the temperature of the pickling solution is controlled at 58°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0043] Example 4: A duplex stainless steel ER2594 welding material disclosed in the present invention is made of the following raw materials in percentage by weight: C: 0.014%; Si: 0.56%; Mn: 0.75%; P: 0.014%; S: 0.014%; Ni: 8.65; Cr: 25.90%; Mo: 3.86%; N: 0.235%; Cu: 0.20%; B: 0.0025%; The balance is iron and unavoidable impurities.

[0044] The welding material shall satisfy the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0045] By controlling the DFW value, CSI value and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance and cracking during hot working are reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly increased, and the high-temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate and suitable for mass production.

[0046] In addition, the present invention also discloses a preparation method of duplex stainless steel ER2594 welding material, which selects waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%), and sequentially performs smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment on the waste stainless steel to obtain the welding material, and the specific implementation method is as follows: S1 first smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then passes through an AOD furnace to sequentially complete decarburization smelting and deoxidation smelting to remove most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 20ppm, and then passes through an LF furnace for refining, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2: pour the molten steel obtained by smelting into the ingot mold, control the superheat temperature of the molten steel to 70°C (casting temperature 1516°C), pay attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 5 minutes, gradually reduce the flow, fill with thin flow, and condense to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 620°C in the low temperature stage for 65 minutes, heats and holds the temperature at 1050°C in the high temperature stage for 95 minutes, heats and holds the temperature at 1300°C in the tapping temperature stage for 130 minutes. After tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats and holds the temperature at 1300°C in the solid solution stage of the billet for 65 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used. The water entry time is controlled at 56s each time, until the surface temperature drops below 150°C. S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground with a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1300℃ at the tapping temperature stage, heated and kept warm for 130 minutes, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 first heats the intermediate billet obtained by grinding and opening the intermediate billet through a step-beam heating furnace, and then heats and holds the temperature at 1050°C in the low temperature stage for 95 minutes, heats to 1260°C in the high temperature stage for 50 minutes, and then goes through furnace rolling. In the rough rolling, dry rolling is adopted. In the rolling process, induction heating is used to heat the rolled piece again. The rolling temperature is set at 1160°C, and the temperature of the rolled piece is controlled at 1080°C during the entire rolling process. Then, the rolled piece is processed by a laying head and a water explosion treatment device in sequence, and the temperature of the rolled wire rod is sharply reduced to below 300°C to reduce the precipitation caused by the cooling time of the wire rod. S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 50 minutes, and the temperature of the pickling solution is controlled at 54°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0047] Example 5: A duplex stainless steel ER2594 welding material disclosed in the present invention is made of the following raw materials in percentage by weight: C: 0.012%; Si: 0.54%; Mn: 0.70%; P: 0.012%; S: 0.012%; Ni: 8.63; Cr: 25.88%; Mo: 3.84%; N: 0.233%; Cu: 0.15%; B: 0.0022%; The balance is iron and unavoidable impurities.

[0048] The welding material shall satisfy the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0049] By controlling the DFW value, CSI value and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance and cracking during hot working are reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly increased, and the high-temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate and suitable for mass production.

[0050] In addition, the present invention also discloses a preparation method of duplex stainless steel ER2594 welding material, which selects waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%), and sequentially performs smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment on the waste stainless steel to obtain the welding material, and the specific implementation method is as follows: S1 firstly smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then sequentially completes decarburization smelting and deoxidation smelting through an AOD furnace to remove most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 30ppm, and then refines through an LF furnace, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2: pour the molten steel obtained by smelting into the ingot mold, control the superheat temperature of the molten steel to 65°C (casting temperature 1511°C), pay attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 3 minutes, gradually reduce the flow, fill with thin flow, and condense to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 600°C in the low temperature stage for 62 minutes, heats and holds the temperature at 980°C in the high temperature stage for 92 minutes, heats and holds the temperature at 1280°C in the steel tapping temperature stage for 120 minutes. After steel tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats and holds the temperature at 1280°C in the solid solution stage of the billet for 62 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used. The water entry time is controlled at 54s each time, until the surface temperature drops below 150°C. S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground with a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1280℃ at the tapping temperature stage, heated and kept warm for 120 minutes, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 first heats the intermediate billet obtained by grinding and opening the intermediate billet through a step-beam heating furnace, and then heats and holds the temperature at 980°C in the low temperature stage for 92 minutes, heats to 1250°C in the high temperature stage for 45 minutes, and then goes through furnace rolling. In the rough rolling, dry rolling is adopted. In the rolling process, induction heating is used to heat the rolled piece again. The rolling temperature is set at 1150°C, and the temperature of the rolled piece is controlled at 1100°C during the entire rolling process. Then, the rolled piece is processed by a laying head and a water explosion treatment equipment in sequence, and the temperature of the rolled wire rod is sharply reduced to below 300°C to reduce the precipitation caused by the cooling time of the wire rod. S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 45 minutes, and the temperature of the pickling solution is controlled at 50°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0051] Example 6: A duplex stainless steel ER2594 welding material disclosed in the present invention is made of the following raw materials in percentage by weight: C: 0.010%; Si: 0.52%; Mn: 0.68%; P: 0.010%; S: 0.010%; Ni: 8.60; Cr: 25.86%; Mo: 3.82%; N: 0.230%; Cu: 0.10%; B: 0.0020%; The balance is iron and unavoidable impurities.

[0052] The welding material shall satisfy the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0053] By controlling the DFW value, CSI value and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance and cracking during hot working are reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly increased, and the high-temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate and suitable for mass production.

[0054] In addition, the present invention also discloses a preparation method of duplex stainless steel ER2594 welding material, which selects waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%), and sequentially performs smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment on the waste stainless steel to obtain the welding material, and the specific implementation method is as follows: S1 first smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then passes through an AOD furnace to complete decarburization smelting and deoxidation smelting in sequence, removes most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 40ppm, and then passes through an LF furnace for refining, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2 pours the molten steel obtained by smelting into the ingot mold, controls the superheat temperature of the molten steel to be 60°C (casting temperature 1506°C), pays attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 3 minutes, gradually reduces the flow, fills with thin flow, and condenses to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 580°C in the low temperature stage for 58 minutes, heats and holds the temperature at 950°C in the high temperature stage for 88 minutes, heats and holds the temperature at 1250°C in the steel tapping temperature stage for 110 minutes. After steel tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats and holds the temperature at 1250°C in the solid solution stage of the billet for 58 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used. The water entry time is controlled at 52s each time, until the surface temperature drops below 150°C. S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground with a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1250℃ at the tapping temperature stage, heated and kept warm for 110 minutes, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 first heats the intermediate billet obtained by grinding and opening the intermediate billet through a step-beam heating furnace, and then heats and holds the temperature at 950°C in the low temperature stage for 88 minutes, heats to 1240°C in the high temperature stage for 40 minutes, and then goes through furnace rolling. In the rough rolling, dry rolling is adopted. In the rolling process, induction heating is used to heat the rolled piece again. The rolling temperature is set at 1140°C, and the temperature of the rolled piece is controlled at 1050°C during the entire rolling process. Then, the rolled piece is processed by a laying head and a water explosion treatment device in sequence, and the temperature of the rolled wire rod is sharply reduced to below 300°C to reduce the precipitation caused by the cooling time of the wire rod. S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 40 minutes, and the temperature of the pickling solution is controlled at 48°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0055] Example 7: A duplex stainless steel ER2594 welding material disclosed in the present invention is made of the following raw materials in percentage by weight: C: 0.008%; Si: 0.51%; Mn: 0.65%; P: 0.008%; S: 0.008%; Ni: 8.58; Cr: 25.84%; Mo: 3.81%; N: 0.225%; Cu: 0.08%; B: 0.0018%; The balance is iron and unavoidable impurities.

[0056] The welding material shall satisfy the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0057] By controlling the DFW value, CSI value and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance and cracking during hot working are reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly increased, and the high-temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate and suitable for mass production.

[0058] In addition, the present invention also discloses a preparation method of duplex stainless steel ER2594 welding material, which selects waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%), and sequentially performs smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment on the waste stainless steel to obtain the welding material, and the specific implementation method is as follows: S1 first smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then passes through an AOD furnace to complete decarburization smelting and deoxidation smelting in sequence, removes most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 50ppm, and then passes through an LF furnace for refining, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2: pour the molten steel obtained by smelting into the ingot mold, control the superheat temperature of the molten steel to 55°C (casting temperature 1501°C), pay attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 3 minutes, gradually reduce the flow, fill with thin flow, and condense to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 560°C in the low temperature stage for 55 minutes, heats and holds the temperature at 920°C in the high temperature stage for 85 minutes, heats and holds the temperature at 1230°C in the steel tapping temperature stage for 100 minutes. After steel tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats and holds the temperature at 1230°C in the solid solution stage of the billet for 55 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used. The water entry time is controlled at 51s each time, until the surface temperature drops below 150°C. S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground with a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1230°C at the tapping temperature stage, heated and kept warm for 100 minutes, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 first heats the intermediate billet obtained by grinding and opening the intermediate billet through a step-beam heating furnace, and then heats and holds the temperature at 920°C in the low temperature stage for 85 minutes, heats to 1230°C in the high temperature stage for 35 minutes, and then goes through furnace rolling. In the rough rolling, dry rolling is adopted. In the rolling process, induction heating is used to heat the rolled piece again. The rolling temperature is set at 1120°C, and the temperature of the rolled piece is controlled at 1080°C during the entire rolling process. Then, the rolled piece is processed by a laying machine and a water explosion treatment device in sequence, and the temperature of the rolled wire rod is sharply reduced to below 300°C to reduce the precipitation caused by the cooling time of the wire rod. S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 35 minutes, and the temperature of the pickling solution is controlled at 44°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0059] Example 8: A duplex stainless steel ER2594 welding material disclosed in the present invention is made of the following raw materials in percentage by weight: C: 0.005%; Si: 0.50%; Mn: 0.60%; P: 0.005%; S: 0.005%; Ni: 8.55; Cr: 25.85%; Mo: 3.80%; N: 0.220%; Cu: 0.05%; B: 0.0015%; The balance is iron and unavoidable impurities.

[0060] The welding material shall satisfy the following formulas (1) to (4) while satisfying the content of each element in the raw material: Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.5.

[0061] By controlling the DFW value, CSI value and harmful elements, the proportion of ferrite formed in the steel is increased, the deformation resistance and cracking during hot working are reduced; by adding boron (B) to the steel, the grain boundary strength of austenitic stainless steel is significantly increased, and the high-temperature plasticity of the material is improved; applying it to the preparation method of the stainless steel wire rod of the present invention can make the preparation process simple, easy to operate and suitable for mass production.

[0062] In addition, the present invention also discloses a preparation method of duplex stainless steel ER2594 welding material, which selects waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%), and sequentially performs smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment on the waste stainless steel to obtain the welding material, and the specific implementation method is as follows: S1 first smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then passes through an AOD furnace to complete decarburization smelting and deoxidation smelting in sequence, removes most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 60ppm, and then passes through an LF furnace for refining, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2 pours the molten steel obtained by smelting into the ingot mold, controls the superheat temperature of the molten steel to be 50°C (casting temperature 1496°C), pays attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 4 minutes, gradually reduces the flow, fills with thin flow, and condenses to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 550°C at a low temperature stage for 50 minutes, heats and holds the temperature at 900°C at a high temperature stage for 80 minutes, heats and holds the temperature at 1200°C at a tapping temperature stage for 100 minutes. After tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats and holds the temperature at 1200°C at a solid solution stage for 50 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used. The water entry time is controlled at 50s each time, until the surface temperature drops below 150°C. S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground with a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1200℃ at the tapping temperature stage, heated and kept warm for 100 minutes, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 firstly heats the intermediate billet obtained by grinding and blanking the intermediate billet through a step-beam heating furnace, and sequentially heats and holds the temperature at 900°C in the low temperature stage for 80 minutes, heats to 1200°C in the high temperature stage for 30 minutes, and then goes through furnace rolling, wherein the rough rolling adopts dry head rolling, and the rolling process uses induction heating to heat the rolled piece again, and the rolling temperature is set at 1100°C, and the temperature of the rolled piece is controlled at 1100°C during the entire rolling process, and then goes through the laying machine and water explosion treatment equipment in sequence, and the temperature of the rolled wire rod is sharply reduced to below 300°C, so as to reduce the precipitation caused by the cooling time of the wire rod; S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 30 minutes, and the temperature of the pickling solution is controlled at 40°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0063] Comparative Example 1: A duplex stainless steel ER2594 welding material disclosed in the present invention, which is different from Example 1 in that it is made of the following raw materials in the following weight percentages: C: 0.018%; Si: 0.45%; Mn: 0.6%; P: 0.025%; S: 0%; Ni: 8.55; Cr: 25.1%; Mo: 3.95%; N: 0.285%; Cu: 0.1%; B: 0%; The balance is iron and unavoidable impurities.

[0064] Among them, the steel ingot obtained by die casting is opened by using an 850 opening machine + chamber regenerative furnace + water tank. After the 14-inch steel ingot is heated, the 850 opening machine is used to open it into a 280mm*300mm intermediate billet. Due to the poor quality of the steel ingot opening, production cannot continue.

[0065] Comparative Example 2: A preparation method of a duplex stainless steel ER2594 welding material disclosed in the present invention, which is different from Example 1 in that waste stainless steel with low P, low Pb (≤0.021%), low Sn (≤0.001%), low As (≤0.001%), low Sb (≤0.001%), and low Bi (≤0.001%) is selected, and the waste stainless steel is successively smelted, die cast, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling, and wire rod surface treatment to obtain the welding material, and the specific implementation method is as follows: S1 first smelts the scrap stainless steel through a 30t electric arc furnace, controls the P content in the remaining molten steel to be ≤0.020%, obtains crude molten steel, and then passes through an AOD furnace to complete decarburization smelting and deoxidation smelting in sequence, removes most of the impurities in the molten steel, controls the C content in the crude molten steel to reach the preset index, and the oxygen activity reaches 50ppm, and then passes through an LF furnace for refining, adds alloys according to the content of each element in the raw material, and adjusts the tapping temperature to obtain smelted molten steel; S2 pours the molten steel obtained by smelting into the ingot mold, controls the superheat temperature of the molten steel to 67°C (casting temperature 1513°C), pays attention to the molten steel not rolling slag during pouring, and the riser shrinkage feeding time should be controlled within 4 minutes, gradually reduces the flow, fills with thin flow, and condenses to obtain the ingot blank; S3 first heats the steel ingot obtained by die casting through a chamber regenerative furnace, and sequentially heats and holds the temperature at 600°C in the low temperature stage for 60 minutes, heats and holds the temperature at 1000°C in the high temperature stage for 90 minutes, heats and holds the temperature at 1292°C in the steel tapping temperature stage for 120 minutes. After steel tapping, the steel ingot is opened by an 850 opening reciprocating rolling mill, and the 14-inch steel ingot is opened into an intermediate billet of 280mm*300mm, and then continues to be heated by a chamber regenerative furnace, and heats and holds the temperature at 1280°C in the solid solution stage of the billet for 60 minutes. The intermediate billet is cooled in stages, and a circulating water tank is used. The water entry time is controlled at 55s each time, until the surface temperature drops below 150°C. S4 In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is firstly ground with a 30-mesh grinding wheel of a grinding wheel grinding machine to remove some crack defects on the surface of the intermediate billet. The pressure is set as a minimum of 25pa according to the program, and the grinding is performed under light pressure for multiple passes. After the billet surface is free of defects, it is further heated by a chamber heat storage furnace to 1280℃ at the tapping temperature stage, heated and kept warm for 120 minutes, and the billet is opened to obtain a 150mm*150mm intermediate billet for rolling wire; S5 firstly heats the intermediate billet obtained by grinding and opening the intermediate billet through a step-beam heating furnace, and sequentially heats and holds the temperature at 1000°C in the low temperature stage for 90 minutes, heats to 1280°C in the high temperature stage for 45 minutes, and then goes through furnace rolling. In which, the rough rolling adopts dry head rolling, and the rolling process uses induction heating to heat the rolled piece again. The rolling temperature is set at 1200°C, and the temperature of the rolled piece is controlled at 1105°C during the entire rolling process. Then, it is sequentially processed by a laying head and a water explosion treatment equipment to sharply reduce the temperature of the rolled wire rod to below 300°C, so as to reduce the precipitation caused by the cooling time of the wire rod; S6 first prepares the pickling solution, which is made of the following raw materials in weight percentage: 15% sulfuric acid, 11% hydrochloric acid, 4% hydrofluoric acid, and the balance is water. Then the wire rod obtained by rolling the intermediate billet is pickled in the pickling solution for 45 minutes, and the temperature of the pickling solution is controlled at 50°C. It is then passivated, neutralized, and dried in sequence to obtain the welding material.

[0066] Test Example 1: The hot working performance of the duplex stainless steel ER2594 welding materials prepared in Example 1 and Comparative Example 2 was tested. The test results are shown in Table 1. Figures 1 to 6 shown.

[0067] Table 1 Example Example 1 Comparative Example 2 DFW 29.07 23.31 CSI 10.29 11.60 Ingot billet yield rate / % 89% 10% Wire rod intermediate billet yield rate / % 86.3% / Tensile strength Rm / MPa 842 846.5 Elongation after fracture A / % 37 37 Sectional shrinkage Z / % 77.5 73 <![CDATA[Sample area / cm 2 > 6.242 6.811 Corrosion temperature / ℃ 25 25 Corrosion time / h 24 24 Corrosion rate / mdd 0.00 0.336 From Table 1, Figures 1 to 6It can be seen that the duplex welding stainless steel manufactured by the composition and process designed by the present invention can effectively solve the problem of scrapping of duplex stainless steel due to surface defects in the intermediate blank from steel ingot to φ5.5 wire, and also solve the problem of poor hot processing performance of the material, avoiding cracking and steel piling problems during continuous rolling; the product water explosion treatment of the present invention reduces the solid solution treatment process of the wire, saves costs, and the product yield rate of the above-mentioned process can reach more than 85%.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A duplex stainless steel ER2594 welding material, characterized by: Made of the following raw materials in percentage by weight: C：≤0.018%； Si: 0.50~0.60%; Mn: 0.60~0.80%; P：≤0.020%； S：≤0.002%； Ni: 8.55~8.70%; Cr：25.80~25.95%； Mo: 3.80~3.90%; N：0.22~0.24%； Cu: ≤0.3%; B：0.0015~0.0030%； The balance is iron and unavoidable impurities.

2. The duplex stainless steel ER2594 welding material according to claim 1, characterized in that: The welding material satisfies the following formulas (1) to (4) while satisfying the content of each element in the raw material; Cr=1.5*Si+0.5*Nb+Cr+Mo (1); Ni=30*(C+N)+0.5*Mn+Ni (2); DFW=138~99.7*(Ni+36.5) / (Cr+17.6) (3); CSI=45.2*C+18.3*N+Mo+Cu+0.65*Ni-297*B-0.14Cr-0.7*Mn (4); Wherein, the corresponding element content in the raw material is substituted in the place of each element symbol in the above formula (1) to (4) according to the weight percentage, DFW is the ferrite content and is controlled within 26 to 29, and CSI is the risk factor of cracking during hot working and is controlled within 10.

5.

3. A method for preparing a duplex stainless steel ER2594 welding material according to claim 1 or 2, characterized in that: The welding material is obtained by selecting waste stainless steel with low P, low Pb, low Sn, low As, low Sb and low Bi, and sequentially subjecting the waste stainless steel to smelting, die casting, two-fire blanking and blank solid solution, intermediate blank grinding and blanking, intermediate blank rolling and wire rod surface treatment.

4. The method for preparing a duplex stainless steel ER2594 welding material according to claim 3, characterized in that: In the smelting process, the scrap stainless steel is first smelted by a 30t electric arc furnace, the P content in the remaining molten steel is controlled to be ≤0.020%, and crude molten steel is obtained. Then, decarburization smelting and deoxidation smelting are sequentially completed by an AOD furnace to remove most of the impurities in the molten steel, the C content in the crude molten steel is controlled to be ≤0.018%, and the oxygen activity reaches 10-60ppm. Then, the LF furnace is used for refining, alloys are added according to the content of each element in the raw material, and the superheated pouring temperature is adjusted to 50-80°C to obtain smelted molten steel.

5. The method for preparing a duplex stainless steel ER2594 welding material according to claim 3, characterized in that: In the mold casting process, the molten steel obtained by smelting is poured into the ingot mold, and the superheat temperature of the molten steel is controlled to be 50-80°C. During pouring, it is noted that the molten steel does not roll up slag, and the riser shrinkage feeding time should be controlled to be 3-5 minutes. The flow is gradually reduced, and the thin flow is filled, and the ingot blank is obtained by condensation.

6. The method for preparing a duplex stainless steel ER2594 welding material according to claim 3, characterized in that: In the process of two-fire blanking and blank solid solution, the steel ingot blank obtained by die casting is first heated by a chamber regenerative furnace, and is heated and kept warm for 50-70 minutes at a low temperature stage of 550-650°C, heated to a high temperature stage of 900-1100°C, heated and kept warm for 80-100 minutes, heated to a steel-tapping temperature stage of 1200-1350°C, heated and kept warm for 100-150 minutes, and after steel-tapping, blanking is performed by an 850 blanking reciprocating rolling mill, and the 14-inch steel ingot blank is blanked to a 280mm*300mm intermediate blank, and then continued to be heated by a chamber regenerative furnace, heated to a blank solid solution stage of 1200-1350°C, heated and kept warm for 50-70 minutes, and the intermediate blank is cooled in stages, and a circulating water tank is used, and the water entry time is controlled at 50-60 seconds each time, until the surface temperature drops below 150°C.

7. The method for preparing a duplex stainless steel ER2594 welding material according to claim 3, characterized in that: In the process of grinding and opening the intermediate billet, the intermediate billet obtained by two-fire opening and solid solution of the billet is first ground with a 30-mesh grinding wheel of a grinding wheel grinder to remove some crack defects on the surface of the intermediate billet, and then continued to be heated in a chamber heat storage furnace to a steel-out temperature stage of 1200-1350° C., heated and kept warm for 100-150 minutes, and opened to obtain a 150mm*150mm intermediate billet for rolling wire.

8. The method for preparing a duplex stainless steel ER2594 welding material according to claim 3, characterized in that: During the intermediate billet rolling process, the intermediate billet obtained by grinding and opening the intermediate billet is first heated by a walking-beam heating furnace, and is heated and kept warm for 80-120 minutes at a low temperature stage of 900-1100°C, and is heated to a high temperature stage of 1280-1300°C for 30-60 minutes, and then rolled out of the furnace, wherein the rough rolling adopts dry head rolling, and the rolling process uses induction heating to heat the rolled piece again, and the temperature is set at 1100-1200°C, and the temperature of the rolled piece is controlled to be ≥1000°C during the entire rolling process, and then it is processed by a laying head and a water explosion treatment equipment in sequence, and the temperature of the rolled wire rod obtained by rolling is sharply reduced to below 300°C, so as to reduce the precipitation caused by the cooling time of the wire rod.

9. The method for preparing a duplex stainless steel ER2594 welding material according to claim 3, characterized in that: In the process of the wire rod surface treatment, the wire rod obtained by rolling the intermediate billet is first pickled in a pickling solution for 30-60 minutes, and the temperature of the pickling solution is controlled to be 40-60° C., and then passivation, neutralization and drying treatments are performed in sequence to obtain the welding material.

10. The method for preparing duplex stainless steel ER2594 welding material according to claim 9, characterized in that: In the process of the wire rod surface treatment, the pickling solution is made of the following raw materials in weight percentage: Sulfuric acid 12~20%; Hydrochloric acid 9~16%; Hydrofluoric acid 3~5%; The balance is water.

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