Electrode flux for sintering of submerged arc welding of weathering steel Q550NH and method of manufacture

Abstract

The present application relates to the Q550NH weathering steel electrode arc sintering flux and preparation method. The Q550NH weathering steel electrode arc sintering flux is made of the following proportion fine powder mixture: fluorite, sillimanite, red magnesia, wollastonite, bauxite, atomized nickel powder, atomized copper powder, rare earth fluoride. On the preparation method, the sintering flux is dry mixed with dry mixer, wet mixing is carried out by adding potassium sodium silicate, then granulation is carried out, drying is carried out at 180-230 DEG C, screening is carried out, then sintering is carried out at 700-900 DEG C high temperature, cooling, lifting, screening, the Q550NH weathering steel electrode arc sintering flux in granular form is obtained. The sintering flux is matched with the corresponding weathering steel arc welding wire, can be used for the welding of Q550NH weathering steel, and presents excellent effect as described herein.

Description

Technical Field

[0001] This invention belongs to the field of welding materials and relates to a sintered flux, specifically a wire-electrode submerged arc welding flux for weathering steel, such as Q550NH. This sintered flux, when used with a corresponding submerged arc welding wire for weathering steel, can be used for welding Q550NH weathering steel and exhibits the excellent results described herein. This invention also relates to a method for preparing this type of wire-electrode submerged arc welding flux for Q550NH weathering steel. Background Technology

[0002] Weathering steel, also known as atmospheric corrosion resistant steel, is a cost-effective low-alloy steel series between ordinary steel and stainless steel. Its main chemical components include phosphorus, copper, nickel, silicon, and chromium. In corrosive environments, it forms a protective rust called "verdigris," which inhibits corrosion and further deterioration. It offers advantages such as no need for protective paint, low maintenance costs, and easy installation. Currently, many infrastructure projects require large quantities of steel. To extend the service life of ordinary steel, the common practice is to coat the surface with an anti-corrosion layer. However, this coating easily causes environmental pollution, and the anti-corrosion layer has a limited lifespan. As the anti-corrosion layer ages, it needs to be repainted and maintained, incurring significant manpower, material, and financial costs, resulting in high maintenance and repair expenses. Therefore, some domestic steel mills have developed and produced uncoated weathering steel for constructing uncoated weathering steel structures such as bridges. Uncoated weathering steel has excellent environmental corrosion resistance, saving construction and maintenance costs while protecting the environment, making it an important direction for the development of steel structures such as bridges. With the improvement of production technology and usage requirements, high-strength weathering steel has become an important component in the development of weathering steel. Using high-strength weathering steel can reduce weight, lower production costs, increase load capacity, and reduce energy consumption. Currently, high-strength weathering steel products have achieved industrialized production in major application areas in China. Therefore, the development of wire-electrode submerged arc welding flux for high-strength weathering steel has significant economic benefits and broad application prospects. In addition to requiring the weld's process and mechanical properties to meet design requirements, uncoated weathering steel also requires a weathering index I ≥ 6.2 for the weld metal. If ordinary sintered flux is used with submerged arc welding wire for weathering steel, on the one hand, the chemical composition of the weld joint will not meet the requirements for atmospheric corrosion resistance, and on the other hand, the low-temperature impact resistance of the weld joint will not meet the design requirements.

[0003] Therefore, there is an urgent need in the field for a high-performance wire electrode submerged arc sintering flux that can be used in conjunction with a corresponding submerged arc welding wire for weathering steel, for welding weathering steel such as Q550NH. Summary of the Invention

[0004] The purpose of this invention is to design a wire electrode submerged arc welding flux for weathering steel, such as Q550NH, for use with submerged arc welding wire for corresponding weathering steel. It is expected that the flux will have good welding process performance, such as the weathering index I of the weld metal being ≥6.2 and the mechanical properties fully meeting the requirements for use.

[0005] Therefore, the first aspect of the present invention provides a wire electrode submerged arc sintering flux for weathering steel Q550NH, characterized in that it is made by mixing fine powders in the following proportions: fluorite, sillimanite, red magnesia, wollastonite, bauxite, atomized nickel powder, atomized copper powder, and rare earth fluoride.

[0006] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that it is made by mixing fine powders in the following proportions: 20-30 parts by weight of fluorite, 15-30 parts by weight of sillimanite, 5-15 parts by weight of red magnesia, 5-15 parts by weight of wollastonite, 20-30 parts by weight of bauxite, 1-5 parts by weight of atomized nickel powder, 1-5 parts by weight of atomized copper powder, and 1-5 parts by weight of rare earth fluoride.

[0007] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that it is made by mixing fine powders in the following proportions: 22-25 parts by weight of fluorite, 20-29 parts by weight of sillimanite, 10-15 parts by weight of red magnesia, 7.5-12.5 parts by weight of wollastonite, 20-22 parts by weight of bauxite, 2-4 parts by weight of atomized nickel powder, 2-3 parts by weight of atomized copper powder, and 2-3 parts by weight of rare earth fluoride.

[0008] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that it is made by mixing fine powders in the following proportions: 25 parts by weight of fluorite, 20 parts by weight of sillimanite, 15 parts by weight of red magnesia, 10 parts by weight of wollastonite, 20 parts by weight of bauxite, 2 parts by weight of atomized nickel powder, 2 parts by weight of atomized copper powder, and 2 parts by weight of rare earth fluoride.

[0009] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that it is made by mixing fine powders in the following proportions: 22 parts by weight of fluorite, 27 parts by weight of sillimanite, 10 parts by weight of red magnesia, 10 parts by weight of wollastonite, 22 parts by weight of bauxite, 2 parts by weight of atomized nickel powder, 2 parts by weight of atomized copper powder, and 2 parts by weight of rare earth fluoride.

[0010] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that it is made by mixing fine powders in the following proportions: 22 parts by weight of fluorite, 29 parts by weight of sillimanite, 10 parts by weight of red magnesia, 10 parts by weight of wollastonite, 22 parts by weight of bauxite, 4 parts by weight of atomized nickel powder, 2 parts by weight of atomized copper powder, and 3 parts by weight of rare earth fluoride.

[0011] According to the first aspect of the present invention, the wire electrode submerged arc welding flux for weathering steel Q550NH is characterized in that it is prepared by mixing fine powders in the following proportions: 22 parts by weight of fluorite, 29 parts by weight of sillimanite, 10 parts by weight of red magnesia, 10 parts by weight of wollastonite, 22 parts by weight of bauxite, 3 parts by weight of atomized nickel powder, 3 parts by weight of atomized copper powder, and 3 parts by weight of rare earth fluoride. For example, it has the proportions described in any of the embodiments.

[0012] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that it is a particulate material prepared from fine powder and binder sodium potassium silicate in the stated proportion.

[0013] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that it is a particulate matter prepared from fine powder and binder sodium potassium silicate in the stated proportion, wherein the weight of sodium potassium silicate used is 22-26% of the total weight of the fine powder.

[0014] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that the potassium-sodium ratio of the binder potassium sodium silicate is 1.5:1.

[0015] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that the modulus of the binder sodium potassium silicate is 2.7.

[0016] According to the first aspect of the present invention, the wire electrode submerged arc welding flux for weathering steel Q550NH is characterized in that the binder sodium potassium silicate has a Baumé degree of 43 at a temperature of 20°C.

[0017] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH is characterized in that the potassium-sodium ratio of the binder potassium sodium silicate is 1.5:1, the modulus is 2.7, and the Baumé degree at 20°C is 43.

[0018] The wire electrode submerged arc sintering flux for weathering steel Q550NH according to the first aspect of the present invention is characterized in that it is prepared by the following process:

[0019] The sintering flux is weighed according to the formula and placed in a dry mixer for dry mixing (e.g., 3-5 minutes, or 4 minutes). After being mixed evenly, it is poured into a wet mixer, and potassium sodium silicate is added for wet mixing (e.g., 2-10 minutes, or 4-6 minutes, or 5 minutes). After being mixed evenly, the wet powder is conveyed to a granulation tray for granulation. After granulation, it is conveyed to a low-temperature furnace and dried at 180-230℃ (e.g., 200℃) for 35-60 minutes (e.g., 45 minutes, to remove 99% of the moisture). Then, it is lifted and screened by an elevator. The semi-finished flux within the standard particle size range is conveyed to a high-temperature kiln for sintering at 700-900℃ (e.g., 800℃) for 50-70 minutes (e.g., 60 minutes). After exiting the kiln, it is cooled, lifted, and screened to obtain granular submerged arc welding flux for Q550NH weathering steel wire electrode (which can be used with corresponding welding wire).

[0020] According to the first aspect of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH has a particle size of 10-60 mesh, for example, a particle size of 10-50 mesh.

[0021] Furthermore, a second aspect of the present invention provides a method for preparing a wire electrode submerged arc sintering flux for weathering steel Q550NH, the wire electrode submerged arc sintering flux for weathering steel Q550NH being prepared by mixing the following fine powders: fluorite, sillimanite, red magnesia, wollastonite, bauxite, atomized nickel powder, atomized copper powder, and rare earth fluoride, characterized in that the method includes the following steps:

[0022] The sintering flux is weighed according to the formula and placed in a dry mixer for dry mixing (e.g., 3-5 minutes, or 4 minutes). After being mixed evenly, it is poured into a wet mixer, and potassium sodium silicate is added for wet mixing (e.g., 2-10 minutes, or 4-6 minutes, or 5 minutes). After being mixed evenly, the wet powder is conveyed to a granulation tray for granulation. After granulation, it is conveyed to a low-temperature furnace and dried at 180-230℃ (e.g., 200℃) for 35-60 minutes (e.g., 45 minutes, to remove 99% of the moisture). Then, it is lifted and screened by an elevator. The semi-finished flux within the standard particle size range is conveyed to a high-temperature kiln for sintering at 700-900℃ (e.g., 800℃) for 50-70 minutes (e.g., 60 minutes). After exiting the kiln, it is cooled, lifted, and screened to obtain granular submerged arc welding flux for Q550NH weathering steel wire electrode (which can be used with corresponding welding wire).

[0023] According to a second aspect of the method of the present invention, the submerged arc welding flux for weathering steel Q550NH is characterized in that it is made by mixing fine powders in the following proportions: 20-30 parts by weight of fluorite, 15-30 parts by weight of sillimanite, 5-15 parts by weight of red magnesia, 5-15 parts by weight of wollastonite, 20-30 parts by weight of bauxite, 1-5 parts by weight of atomized nickel powder, 1-5 parts by weight of atomized copper powder, and 1-5 parts by weight of rare earth fluoride.

[0024] According to a second aspect of the present invention, the method is characterized in that the wire electrode submerged arc sintering flux for weathering steel Q550NH is prepared by mixing fine powders in the following proportions: 22-25 parts by weight of fluorite, 20-29 parts by weight of sillimanite, 10-15 parts by weight of red magnesia, 7.5-12.5 parts by weight of wollastonite, 20-22 parts by weight of bauxite, 2-4 parts by weight of atomized nickel powder, 2-3 parts by weight of atomized copper powder, and 2-3 parts by weight of rare earth fluoride.

[0025] According to a second aspect of the method of the present invention, the submerged arc welding flux for weathering steel Q550NH is made by mixing fine powders in the following proportions: 25 parts by weight of fluorite, 20 parts by weight of sillimanite, 15 parts by weight of red magnesia, 10 parts by weight of wollastonite, 20 parts by weight of bauxite, 2 parts by weight of atomized nickel powder, 2 parts by weight of atomized copper powder, and 2 parts by weight of rare earth fluoride.

[0026] According to a second aspect of the method of the present invention, the submerged arc welding flux for weathering steel Q550NH is made by mixing fine powders in the following proportions: 22 parts by weight of fluorite, 27 parts by weight of sillimanite, 10 parts by weight of red magnesia, 10 parts by weight of wollastonite, 22 parts by weight of bauxite, 2 parts by weight of atomized nickel powder, 2 parts by weight of atomized copper powder, and 2 parts by weight of rare earth fluoride.

[0027] According to a second aspect of the method of the present invention, the submerged arc welding flux for weathering steel Q550NH is made by mixing fine powders in the following proportions: 22 parts by weight of fluorite, 29 parts by weight of sillimanite, 10 parts by weight of red magnesia, 10 parts by weight of wollastonite, 22 parts by weight of bauxite, 4 parts by weight of atomized nickel powder, 2 parts by weight of atomized copper powder, and 3 parts by weight of rare earth fluoride.

[0028] According to a second aspect of the present invention, the method is characterized in that the wire electrode submerged arc sintering flux for weathering steel Q550NH is prepared by mixing fine powders in the following proportions: 22 parts by weight of fluorite, 29 parts by weight of sillimanite, 10 parts by weight of red magnesia, 10 parts by weight of wollastonite, 22 parts by weight of bauxite, 3 parts by weight of atomized nickel powder, 3 parts by weight of atomized copper powder, and 3 parts by weight of rare earth fluorides. For example, it has the proportions described in any of the embodiments.

[0029] According to a second aspect of the method of the present invention, the weathering steel Q550NH wire electrode submerged arc sintering flux is a particulate matter prepared from fine powder and binder sodium potassium silicate in the stated proportion.

[0030] According to a second aspect of the method of the present invention, the weathering steel Q550NH wire electrode submerged arc sintering flux is a particulate matter prepared from fine powder and binder sodium potassium silicate in the stated proportion, wherein the weight of sodium potassium silicate used is 22-26% of the total weight of the fine powder.

[0031] According to a second aspect of the method of the present invention, the method is characterized in that the potassium-sodium ratio of the adhesive sodium potassium silicate is 1.5:1.

[0032] According to a second aspect of the method of the present invention, the modulus of the adhesive sodium potassium silicate is 2.7.

[0033] According to a second aspect of the present invention, the method is characterized in that the adhesive sodium potassium silicate has a Baume degree of 43 at a temperature of 20°C.

[0034] According to a second aspect of the present invention, the method is characterized in that the potassium-sodium ratio of the adhesive sodium potassium silicate is 1.5:1, the modulus is 2.7, and the Baumé degree at 20°C is 43.

[0035] According to a second aspect of the method of the present invention, the wire electrode submerged arc sintering flux for weathering steel Q550NH has a particle size of 10-60 mesh, for example, a particle size of 10-50 mesh.

[0036] Any embodiment of any aspect of the present invention can be combined with other embodiments, as long as they do not contradict each other. Furthermore, any technical feature in any embodiment of any aspect of the present invention can be applied to the same technical feature in other embodiments, as long as they do not contradict each other. The present invention will now be further described.

[0037] All references cited in this invention are incorporated herein by reference in their entirety, and in the event of any inconsistency between the meanings expressed in these references and those expressed herein, the meanings expressed herein shall prevail. Furthermore, the various terms and phrases used in this invention have their general meanings known to those skilled in the art; however, this invention still seeks to provide a more detailed explanation and interpretation of these terms and phrases, and in the event of any inconsistency between the mentioned terms and their known meanings and those expressed herein, the meanings expressed herein shall prevail.

[0038] The various terms and phrases used in this invention have their general meanings known to those skilled in the art. Nevertheless, this invention still intends to provide a more detailed description and explanation of these terms and phrases. In the event of any inconsistency between the terms and phrases mentioned and their known meanings, the meanings expressed in this invention shall prevail.

[0039] In this invention, the term "parts by weight" refers to the relative amounts of the components in the flux coating of the welding wire of this invention. "Parts by weight" can be an absolute weight (e.g., mg, g, or kg) or a weight percentage (e.g., weight % or wt%). Of course, when expressed as a weight percentage (e.g., weight % or wt%), a preferred embodiment is that the sum of the components is 100%.

[0040] In this invention, the various ingredients used are known in the art, such as fluorite, sillimanite, red magnesia, wollastonite, bauxite, atomized nickel powder, atomized copper powder, rare earth fluoride, and potassium sodium water glass. These materials all have the meanings known in the art. They are all raw materials commonly used by those skilled in the art in the preparation of welding materials, and they can all be purchased directly from the market under the above-mentioned names.

[0041] The flux obtained by this invention has excellent technical effects as described in the context of this invention, such as, but not limited to, the following advantages:

[0042] This invention uses a variety of composite compounds to add corresponding components. During the welding process, the decomposition of the compounds is mainly due to the breaking of chemical bonds. To break the well-bonded chemical bonds, heat absorption is required, which can relatively reduce the heat energy during the welding process and reduce the possibility of hot cracks.

[0043] The present invention refines the grains and increases the amount of acicular ferrite by adding rare earth fluoride to the sintering flux, thereby improving the low-temperature impact toughness of the weld metal.

[0044] This invention utilizes Ni and Cu alloying elements in the sintering flux to meet the requirements for the mechanical properties and weather resistance index of the weld metal.

[0045] This invention uses a sintering flux that is typically dried at 180~230℃ to remove 99% of the moisture, followed by high-temperature sintering at 700~900℃. This ensures that the resulting flux has high strength and low hygroscopicity, thereby guaranteeing the diffusible hydrogen and oxygen content of the weld overlay metal.

[0046] The present invention incorporates CaF2 and Al2O3 as the main slag-forming agents, which effectively inhibits the transfer of harmful elements such as H and O to the weld.

[0047] This invention rationally adjusts the proportions of each component of the flux and designs a reasonable flux slag system, which effectively adjusts the viscosity, surface tension, and fluidity of the slag. When the flux is applied, the welding process is stable and the slag removal performance is excellent. Detailed Implementation

[0048] The invention can be further described through the following embodiments; however, the scope of the invention is not limited to the following embodiments. Those skilled in the art will understand that various changes and modifications can be made to the invention without departing from its spirit and scope. The materials and methods used in the experiments are described generally and / or specifically. Although many materials and methods of operation used to achieve the objectives of the invention are well known in the art, the invention is still described in as much detail as possible herein.

[0049] In the following specific examples of flux preparation, the formulation is expressed in weight ratios (g), but in actual feeding, this ratio is always used, and the total amount fed each time is greater than 10 kg. In the specific examples of this invention, unless otherwise specified, the welding wire used when evaluating the flux performance is HSNHQ70.

[0050] Example 1: Wire electrode submerged arc welding flux for weathering steel Q550NH

[0051] In this embodiment, four types of flux were prepared, numbered N1-N4. The weight ratio of each component of the four sintering fluxes is shown in Table 1.

[0052] Table 1: Flux Composition and Weight Ratio of Each Component (g)

[0053]

[0054] The flux preparation method is as follows:

[0055] The sintering flux is weighed according to the formula and the total weight is checked. It is then put into a dry mixer and dry-mixed for 3-5 minutes (4 minutes in this example). After being dry-mixed evenly, it is poured into a wet mixer and potassium sodium silicate (24% of the total weight of dry powder) is added and wet-mixed for 2-10 minutes (5 minutes in this example). After being wet-mixed evenly, the wet powder is sent to a granulation tray by a conveyor belt for granulation. After granulation, it is sent to a low-temperature furnace by a conveyor belt and dried at 180-230℃ (200℃ in this example) for 35-60 minutes (45 minutes in this example, removing 99% of the moisture). Then it is lifted by an elevator and screened. The semi-finished flux within the standard particle size range after screening is sent to a high-temperature kiln for sintering at 700-900℃ (800℃ in this example) for 50-70 minutes (60 minutes in this example). After exiting the kiln, it is cooled, lifted, screened (10-50 mesh), and packaged to produce the finished flux.

[0056] The potassium sodium silicate used in this embodiment has a potassium-to-sodium ratio of 1.5:1, a modulus of 2.7, and a Baumé degree of 43 at 20°C.

[0057] Welding tests were conducted by combining the prepared fluxes with the corresponding submerged arc welding wires for weathering steel. The steel plate used for the tests was Q550NH weathering steel with a thickness of 20 mm and a welding wire diameter of 4.0 mm. The general welding process parameters are shown in Table 2.

[0058] Table 2: Welding process parameters

[0059]

[0060] Test plates were welded using flux and submerged arc welding wire, and the welding process performance and mechanical properties of the deposited metal were tested according to GB / T 12470-2003 standard. The welding power source was DC reverse polarity, the welding current was 550A, the welding voltage was 31V, the welding speed was 42cm / min, the weld extension was 30mm, and the interpass temperature was 150℃.

[0061] The test results of welding process performance are shown in Table 3. Excellent is scored as 9 points, good as 8 points, and average as 7 points. The welding process performance scores of each flux are calculated. The scores of fluxes N1 to N4 are 29, 28, 30, and 35 points, respectively, showing that the welding process performance of flux N4 is significantly better than the other three.

[0062] Table 3: Flux Welding Process Performance

[0063]

[0064] In addition, the weathering index of the welding wire and the deposited metal was tested according to methods known in the art. The results are shown in Table 4. The weathering index I values ​​of the deposited metal and the welding wire used by each flux are all greater than 6.2. However, similar to the welding process performance results, the weathering index of the deposited metal formed by N4 flux is significantly greater than the other three.

[0065] Table 4: Weather Resistance Index of Welding Wire and Deposited Metal

[0066]

[0067] The mechanical properties of the weld metal obtained by N4 flux were tested, and the test results are shown in Table 5. The results show that the weld metal obtained by N4 flux has excellent mechanical properties.

[0068] Table 5: Test Results of Mechanical Properties of Deposited Metal

[0069]

[0070] Example 2: Wire electrode submerged arc welding flux for weathering steel Q550NH

[0071] According to TB / T2375-1993 "Test Method for Cyclic Immersion Corrosion of Weathering Steel for Railway Use", cyclic immersion corrosion tests were further conducted on the weld metal obtained from welding with fluxes N1 to N4 in Example 1. Q235A steel was selected for the test plates. The corrosion test samples were prepared from weld metal test plates, with dimensions of 450 mm × 200 mm × 20 mm. The corrosion test equipment was an immersion-wet / dry cyclic testing machine. The test cycle was 75 h. The weld metal was compared with a 09CuPTiRe sample; the corrosion weight loss rate of the 09CuPTiRe sample was 1.0575 g / m³. 2 / h, relative corrosion rate 100%, the corrosion weight loss of the four weld samples obtained in Example 1 ranged from 1.0577 to 1.0923 g / m 2 Within a certain range ( / h); the relative corrosion rate ranges from 100.6% to 101.2%, for example, the corrosion weight loss rate of the deposited metal sample obtained by welding with N4 flux is 1.0577 g / m³. 2 / h, with a relative corrosion rate of 100.6%.

[0072] Example 3: Submerged arc welding flux for weathering steel Q550NH

[0073] This embodiment also provides two fluxes, referred to as N5 and N6, respectively, with reference to Embodiment 1. The N5 flux formula is: 22g fluorite, 29g sillimanite, 10g red magnesia, 10g wollastonite, 22g bauxite, 3g atomized nickel powder, 3g atomized copper powder, and 3g rare earth fluoride. The preparation method is the same as in Embodiment 1, but the amount of potassium sodium silicate added is 22% of the total weight of the dry powder, resulting in the N5 flux. The N6 flux formula is: 22g fluorite, 29g sillimanite, 10g red magnesia, 10g wollastonite, 22g bauxite, 3g atomized nickel powder, 3g atomized copper powder, and 3g rare earth fluoride. The preparation method is the same as in Embodiment 1, but the amount of potassium sodium silicate added is 26% of the total weight of the dry powder, resulting in the N6 flux.

[0074] Next, the performance parameters of fluxes N5 and N6 were tested according to the testing methods in Example 1, and the deposited metal was subjected to a periodic wetting corrosion test according to the method in Example 2. The results showed that the corrosion weight loss rate of the deposited metal sample obtained by welding with flux N5 was 1.0597 g / m. 2 / h, the relative corrosion rate was 100.9%; the corrosion weight loss rate of the deposited metal sample obtained by welding with N6 flux was 1.0821 g / m 2The relative corrosion rate was 101.1%. Welding process performance scores were 36 and 35 respectively, with weathering resistance indices of deposited metal of 7.36 and 7.24, tensile strengths of 662 MPa and 683 MPa, yield strengths of 734 MPa and 727 MPa, and elongation of 25.3% and 26.8%. The -40℃ impact values ​​in five tests were all excellent (N5: 162 J, 153 J, 167 J, 148 J, 159 J; N6: 152 J, 146 J, 162 J, 157 J, 153 J), and the performance results were comparable to those of flux N4. These results indicate that the N4 formulation can be mixed with 22%–26% potassium sodium silicate and has excellent effects. The results also show that although the material ratios of fluxes N1–N4 showed no regularity or significant differences, N4 exhibited significantly superior results within this irregularity.

[0075] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A wire electrode submerged arc sintering flux for weathering steel Q550NH, characterized in that, It is a granular material prepared by mixing fine powder and sodium potassium silicate as a binder in the following proportions: 22 parts by weight of fluorite, 29 parts by weight of sillimanite, 10 parts by weight of red magnesia, 10 parts by weight of wollastonite, 22 parts by weight of bauxite, 3 parts by weight of atomized nickel powder, 3 parts by weight of atomized copper powder, and 3 parts by weight of rare earth fluoride; the weight of sodium potassium silicate used is 22-26% of the total weight of the fine powder.

2. The wire electrode submerged arc sintering flux for weathering steel Q550NH according to claim 1, characterized in that, It is a particulate matter prepared by the fine powder and the binder sodium potassium silicate in the specified proportion, wherein the weight of sodium potassium silicate used is 24% of the total weight of the fine powder.

3. The wire electrode submerged arc sintering flux for weathering steel Q550NH according to claim 1, characterized in that, The potassium-sodium ratio of the adhesive potassium sodium silicate is 1.5:

1.

4. The wire electrode submerged arc sintering flux for weathering steel Q550NH according to claim 1, characterized in that, The modulus of the adhesive sodium potassium silicate is 2.

7.

5. The wire electrode submerged arc sintering flux for weathering steel Q550NH according to claim 1, characterized in that, The adhesive, sodium potassium silicate, has a Baumé degree of 43 at a temperature of 20°C.

6. The wire electrode submerged arc sintering flux for weathering steel Q550NH according to claim 1, characterized in that, The binder, potassium sodium silicate, has a potassium-to-sodium ratio of 1.5:1, a modulus of 2.7, and a Baumé degree of 43 at 20°C.

7. The wire electrode submerged arc sintering flux for weathering steel Q550NH according to claim 1, characterized in that, It is prepared by the following process: the sintering flux is weighed according to the formula and mixed in a dry mixer for 3 to 5 minutes. After being mixed evenly, it is poured into a wet mixer, potassium sodium silicate is added and wet mixed for 4 to 6 minutes. After being wet mixed evenly, the wet powder is sent to a granulation tray by a conveyor belt for granulation. After granulation, it is sent to a low temperature furnace by a conveyor belt and dried at 180-230℃ for 35-60 minutes to remove 99% of the moisture. Then it is lifted and screened by an elevator. The semi-finished flux within the standard particle size range after screening is sent to a high temperature kiln for sintering at 700-900℃ for 50-70 minutes. After exiting the kiln, it is cooled, lifted and screened to obtain granular sintering flux for submerged arc welding of Q550NH weathering steel.

8. The wire electrode submerged arc sintering flux for weathering steel Q550NH according to claim 1, has a particle size of 10-50 mesh.

9. A method for preparing the wire electrode submerged arc sintering flux for weathering steel Q550NH as described in any one of claims 1 to 6, comprising the following steps: weighing the raw materials according to the formula, placing them in a dry mixer and dry mixing for 3 to 5 minutes, and after uniform dry mixing, pouring them into a wet mixer, adding potassium sodium silicate and wet mixing for 4 to 6 minutes, and after uniform wet mixing, sending the wet powder to a granulation tray via a conveyor belt for granulation, and after granulation, sending it to a low-temperature furnace via a conveyor belt, drying it at 180-230℃ for 35-60 minutes to remove 99% of the moisture, then lifting it by an elevator and sieving it, and sending the sieved semi-finished flux within the standard particle size range to a high-temperature kiln for sintering at 700-900℃ for 50-70 minutes, and after exiting the kiln, cooling, lifting, and sieving to obtain granular wire electrode submerged arc sintering flux for weathering steel Q550NH.

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