Efficient submerged arc welding wire suitable for ocean engineering large thick plate and application of efficient submerged arc welding wire

Abstract

The invention provides an efficient submerged arc welding wire suitable for ocean engineering large thick plates and application of the efficient submerged arc welding wire. The submerged arc welding wire comprises the following components in percentage by mass: 0.05 to 0.08 percent of C; 1.20% to 1.40% of Mn; cr: 0.05 to 0.10%; 0.05% to 0.10% of Mo; 0.20% to 0.60% of Ni; 0.005 to 0.008 percent of Mg (magnesium); 0.06 to 0.10 percent of Ti; the content of Hf is 0.005 to 0.01 percent; s < = 0.004%; p < = 0.006%; h is less than 10 ppm; n: 0.0020% to 0.0030%; o: 0.0020% to 0.0030%; and the balance of Fe and inevitable impurities. The submerged arc welding wire meets the requirement for efficient welding of 50-55 Kg of maritime work large thick plates, meets double-wire welding large heat input welding, still has good performance when the heat input quantity is 50-100 KJ / cm, the tensile strength of the submerged arc welding wire can reach 550 MPa or above, the yield strength is 420 MPa or above, the yield ratio is smaller than or equal to 0.88, the low-temperature impact toughness is stable, and the impact energy at the temperature of-40 DEG C is 130 J or above.

Description

Technical Field

[0001] The invention relates to the technical field of welding materials, and in particular to a high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering and application thereof. Background Art

[0002] With the increasing demand for energy in the world and the depletion of onshore oil resources, the development of marine energy has become a hot spot for development in various countries, including the development of offshore wind power and offshore oil and gas resources. Offshore platforms are special places for operations on the ocean. Their service life is 50% longer than that of ships. The steel plates used must have high strength, high toughness, fatigue resistance, lamellar tearing resistance, good weldability and seawater corrosion resistance. In order to avoid serious welding defects such as cracks after welding, heat treatment is required. With the continuous increase in the capacity of offshore wind power units and the depth of offshore oil development, the marine structure is getting heavier, the volume of the structure and the thickness of the steel plate used are also increasing. At the same time, the amount of welding filling is also increasing exponentially. Therefore, in terms of large thick plate welding, there is an urgent need for welding materials that meet the requirements of heat treatment and efficient welding at the same time.

[0003] 50-55Kg grade steel plates, such as DH36, EH36, FH36, DH42, EH42, FH42, commonly use submerged arc welding wires such as H08MnA and H10Mn2. Such welding wires can meet the requirements of -40℃ low temperature impact under conventional welding conditions, but are less efficient when welding thick plates, and their performance deteriorates severely when welding with high line energy. They have poor crack resistance and cannot meet the requirements of 620℃ / 6h post-weld heat treatment after welding. Therefore, there is an urgent need for a high-efficiency submerged arc welding wire suitable for thick plates in marine engineering to solve the above problems. Summary of the invention

[0004] In order to solve the above problems, on the one hand, the present invention provides a high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering, wherein the submerged arc welding wire comprises the following components by mass percentage: C: 0.05-0.08%; Mn: 1.20-1.40%; Cr: 0.05-0.10%; Mo: 0.05-0.10%; Ni: 0.20-0.60%; Mg: 0.005-0.008%; Ti: 0.06-0.10%; Hf: 0.005-0.01%; S≤0.004%; P≤0.006%; H<10ppm; N: 0.0020-0.0030%; O: 0.0020-0.0030%; the rest are Fe and unavoidable impurities.

[0005] Furthermore, the submerged arc welding wire includes the following components in mass percentage: C: 0.07%; Mn: 1.25%; Cr: 0.07%; Mo: 0.08%; Ni: 0.5%; Mg: 0.0055%; Ti: 0.08%; Hf: 0.0055%; S: 0.003%; P: 0.005%; H: 3ppm; N: 0.0022%; O: 0.0023%; the rest is Fe and unavoidable impurities.

[0006] Furthermore, in the submerged arc welding wire, the ratio of the sum of the contents of the Mg element and the Hf element w(Mg+Hf) to the content of the O element w(O) w(Mg+Hf) / w(O) is 5-6.

[0007] Furthermore, the diameter of the oxide MgO formed in the submerged arc welding wire is 30-60 nm.

[0008] Furthermore, the diameter of the dispersed TiN formed in the submerged arc welding wire is 20-50 nm.

[0009] Furthermore, the diameter of the submerged arc welding wire is 2.4 mm-5.0 mm.

[0010] On the other hand, the present invention also provides an application of the high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering as described above, wherein the submerged arc welding wire is used in combination with a silicon-calcium type sintered flux.

[0011] Furthermore, the basicity of the calcium-silicon type sintered flux is 2.2-2.6, the particle size is 10-60 mesh, and the flux is dehumidified at 380-400° C. for at least 2 hours before use.

[0012] Furthermore, the silicon-calcium type sintered flux is TM.SJ55HG flux.

[0013] The design principles of the main components of the high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering of the present invention are as follows:

[0014] C mainly plays a role in ensuring the strength of weld metal during high-energy welding through solid solution strengthening and carbide precipitation, but it has a negative impact on H resistance. 2 S has a negative impact on corrosion. On the one hand, due to the formation of chromium carbide, chromium is generated near the grain boundary. On the other hand, it will cause the segregation of manganese and phosphorus elements, forming a banded structure, which increases the probability of cracks. Therefore, the C content is controlled between 0.05-0.08%, and the C content in the deposited metal is ensured to be between 0.04-0.06%, which can not only ensure the mechanical properties during high-line energy welding, but also effectively reduce H 2 S corrosion.

[0015] Mn is mainly a deoxidizer and desulfurizer. Through precise composition control, it adjusts the oxygen content in the weld to ensure that the size of the high-temperature oxide MgO is at the nanometer level. On the other hand, it improves the strength and toughness of the weld during high-energy welding through solid solution strengthening. Therefore, the manganese content is controlled at 1.20-1.40%, which can ensure the acquisition of excellent performance weld joints.

[0016] Cr and Mo elements are mainly used to make up for the insufficient strength of weld metal caused by low carbon and low manganese design, so as to achieve high-efficiency welding with large wire energy.

[0017] The Ni element is mainly used to improve the low-temperature impact toughness of the weld, but too high Ni will form a martensite phase, so it is strictly controlled not to exceed 1%, increasing the absorption effect of the weld on H, resulting in an increase in the tendency of hydrogen sulfide stress corrosion cracking of the metal. By controlling the Ni content to 0.20-0.60%, the low-temperature impact toughness and hydrogen sulfide stress corrosion cracking can be effectively balanced.

[0018] Mg / Hf elements control the oxygen content. When the Mg content is 0.005-0.008% and the Hf content is 0.005-0.01%, nano-sized high-temperature oxides MgO and HfO can be formed. 2 , the size is controlled at 30-60nm, which can effectively improve the stability of the weld structure during high-line energy welding and improve the low-temperature impact performance.

[0019] As a trace alloying element, Ti mainly plays the role of fine grain strengthening and dispersion strengthening. By forming stable compounds with elements such as C, O and N, and controlling the cooling rate to disperse and precipitate in the weld, the toughness of the weld can be improved while the strength can be improved. By controlling the N content, the mass percentage of Ti is controlled at 0.06-0.10%, and the size of TiN formed in the weld is 20-50nm, which is beneficial to toughness and heat treatment stability.

[0020] As harmful impurity elements, S and P will seriously deteriorate the impact properties of weld metal, reduce weld toughness, and increase the risk of joint cracking. The low S and P design can control S below 0.004% and P below 0.006%, which can effectively reduce the damage of the two harmful elements.

[0021] N significantly improves strength, reduces toughness, makes welds brittle, and easily forms N pores to reduce joint performance during welding. However, N in an appropriate range forms nanoparticles with Ti, which is beneficial to dispersion strengthening and enhancing weld performance. Therefore, N is controlled at 0.0020-0.0030% to obtain nano-level TiN.

[0022] H and O are harmful elements in gas. The high-pressure hydrogen gas cluster formed by H is the main driving force for crack propagation, increasing the risk of cracking in weld joints. O can form oxides with almost all metals. Large oxide inclusions are also the main source of corrosion and failure. Purification design plays an important role in improving the uniformity of joint structure.

[0023] The high-efficiency submerged arc welding wire suitable for thick plates in marine engineering provided by the present invention reduces the segregation of carbide and sulfide inclusions in the weld through ultra-low S, low P and low H design, forms nano-scale Mg high-temperature oxide through the welding wire, prevents grain growth and coarsening, and ensures impact toughness under high wire energy; TiN and rare earth oxide HfO are formed by adding Ti and part of rare earth Hf 2 Dispersion strengthening prevents grain growth and promotes ferrite formation. By precisely controlling the content of O and N in the welding wire, the size of Mg high-temperature oxides, TiN and rare earth oxides is controlled within a reasonable range; by adding appropriate amounts of alloy Mo and Cr to compensate for strength loss, the requirements for post-weld heat treatment are met. The submerged arc welding wire is used in conjunction with silicon-calcium sintered flux to meet the requirements for efficient welding of 50-55Kg offshore thick plates.

[0024] The submerged arc welding wire of the present invention has the content of each element precisely controlled, is rolled into a wire rod after smelting, and the wire rod is made into the submerged arc welding wire by using a copper plating process or a copper-free process.

[0025] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0026] 1) The submerged arc welding wire provided by the present invention meets the requirements of efficient welding of 50-55Kg thick marine plates through the design of various components, meets the requirements of double-wire welding with large input energy, has high welding efficiency, and still has good performance when the heat input is 50-100KJ / cm. Its tensile strength can reach more than 550MPa, its yield strength is more than 420MPa, its yield strength ratio is ≤0.88, its low-temperature impact toughness is stable, and its impact energy at -40℃ is more than 130J.

[0027] 2) The submerged arc welding wire provided by the present invention meets the post-weld heat treatment requirement of 620°C / 6h, has a tensile strength of more than 550MPa, a yield strength of more than 420MPa, a yield strength ratio of ≤0.88, stable low-temperature impact toughness, and an impact energy of more than 150J at -40°C.

[0028] 3) The submerged arc welding wire provided by the present invention has excellent crack resistance and meets the requirement of CTOD value ≥ 0.30 mm at -10°C. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The invention provides a high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering. The submerged arc welding wire comprises the following components in percentage by mass: C: 0.05-0.08%; Mn: 1.20-1.40%; Cr: 0.05-0.10%; Mo: 0.05-0.10%; Ni: 0.20-0.60%; Mg: 0.005-0.008%; Ti: 0.06-0.10%; Hf: 0.005-0.01%; S≤0.004%; P≤0.006%; H<10ppm; N: 0.0020-0.0030%; O: 0.0020-0.0030%; the rest is Fe and unavoidable impurities.

[0031] The composition and performance of the submerged arc welding wire of the present invention are specifically described below through five embodiments.

[0032] Table 1: Submerged arc welding wire composition and content (mass percentage, %)

[0033] Example 1 Example 2 Example 3 Example 4 Example 5 C 0.05 0.065 0.07 0.075 0.060 Mn 1.15 1.20 1.25 1.32 1.40 Cr 0.10 0.08 0.07 0.06 0.05 Ni 0.35 0.40 0.5 0.55 0.60 Mo 0.10 0.09 0.08 0.06 0.07 Mg 0.006 0.0050 0.0055 0.008 0.007 Ti 0.08 0.09 0.08 0.06 0.10 Hf 0.008 0.007 0.0065 0.005 0.0055 S 0.0025 0.0035 0.003 0.0035 0.0020 P 0.0055 0.0050 0.0050 0.0054 0.0046 N <![CDATA[20*10 -4 ]]> <![CDATA[24*10 -4 ]]> <![CDATA[22*10 -4 ]]> <![CDATA[29*10 -4 ]]> <![CDATA[25*10 -4 ]]> H <![CDATA[2.6*10 -4 ]]> <![CDATA[2.2*10 -4 ]]> <![CDATA[2.0*10 -4 ]]> <![CDATA[2.8*10 -4 ]]> <![CDATA[2.1*10 -4 ]]> O <![CDATA[28*10 -4 ]]> <![CDATA[22*10 -4 ]]> <![CDATA[23*10 -4 ]]> <![CDATA[22*10 -4 ]]> <![CDATA[24*10 -4 ]]> Fe the remaining the remaining the remaining the remaining the remaining

[0034] The size of the oxide MgO formed in the submerged arc welding wire prepared in Examples 1-5 is 30-60 nm, and the size of the dispersed TiN formed is 20-50 nm.

[0035] The submerged arc welding wire prepared in the above-mentioned embodiments 1-5 is used in conjunction with silicon-calcium type sintered flux during welding, and the sintered flux is preferably TM.SJ55HG flux, the flux basicity is controlled at 2.2-2.6, the particle size is 10-60 mesh, and the flux is dehumidified at 380-400°C for at least 2 hours before use. The submerged arc welding wire meets the requirements for efficient welding of 50-55Kg thick offshore plates, can be used for double-wire welding with high input energy, and can also meet the requirements for post-weld heat treatment of 620°C / 6h.

[0036] The mechanical properties of the deposited metal after welding using the submerged arc welding wire obtained in Examples 1-5 are shown in Table 2 below.

[0037] Table 2: Mechanical properties of deposited metal

[0038]

[0039]

[0040] The submerged arc welding wire prepared in the above embodiments 1-5 not only meets the requirements of double-wire welding with high input energy, but also meets the requirements of post-weld heat treatment at 620°C / 6h. The tensile strength can reach above 550MPa, the yield strength is above 420MPa, the yield strength ratio is ≤0.88, the low-temperature impact toughness is stable, and the impact energy at -40°C is above 130J.

[0041] The crack resistance (CTOD) performance of the submerged arc welding wire obtained using Examples 1-5 is shown in Table 3 below.

[0042] Table 3: Crack resistance (CTOD) experimental performance

[0043] CTOD(mm) Example 1 0.56、0.46、0.63 Example 2 0.49、0.64、0.44 Example 3 1.52、1.91、1.61 Example 4 1.4、0.66、0.96 Example 5 0.66、0.54、0.41

[0044] It can be seen from Table 3 that the high-efficiency submerged arc welding wire suitable for thick plates in marine engineering has excellent crack resistance and meets the requirement of CTOD value ≥ 0.30 mm at -10°C.

[0045] Those skilled in the art will appreciate that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Although embodiments of the present invention have been described, it should be understood that the present invention should not be limited to this embodiment, and those skilled in the art can make changes and modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering, characterized in that: The submerged arc welding wire comprises the following components by mass percentage: C: 0.05-0.08%; Mn: 1.20-1.40%; Cr: 0.05-0.10%; Mo: 0.05-0.10%; Ni: 0.20-0.60%; Mg: 0.005-0.008%; Ti: 0.06-0.10%; Hf: 0.005-0.01%; S≤0.004%; P≤0.006%; H<10ppm; N: 0.0020-0.0030%; O: 0.0020-0.0030%; the rest is Fe and inevitable impurities.

2. The high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering as claimed in claim 1, characterized in that: The submerged arc welding wire includes the following components in mass percentage: C: 0.07%; Mn: 1.25%; Cr: 0.07%; Mo: 0.08%; Ni: 0.5%; Mg: 0.0055%; Ti: 0.08%; Hf: 0.0055%; S: 0.003%; P: 0.005%; H: 3ppm; N: 0.0022%; O: 0.0023%; the rest is Fe and unavoidable impurities.

3. The high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering as claimed in claim 1, characterized in that: In the submerged arc welding wire, the ratio of the sum of the contents of Mg element and Hf element w(Mg+Hf) to the content of O element w(O) w(Mg+Hf) / w(O) is 5-6.

4. The high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering as claimed in claim 1, characterized in that: The diameter of the oxide MgO formed in the submerged arc welding wire is 30-60nm.

5. The high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering as claimed in claim 1, characterized in that: The diameter of the dispersed TiN formed in the submerged arc welding wire is 20-50nm.

6. The high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering as claimed in claim 1, characterized in that: The diameter of the submerged arc welding wire is 2.4mm-5.0mm.

7. The use of the high-efficiency submerged arc welding wire suitable for large and thick plates in marine engineering as claimed in any one of claims 1 to 6, characterized in that: The submerged arc welding wire is used in combination with silicon-calcium type sintered flux.

8. The use of high-efficiency submerged arc welding wire suitable for thick plates in marine engineering as claimed in claim 7, characterized in that: The basicity of the silicon-calcium type sintered flux is 2.2-2.6, the particle size is 10-60 meshes, and the flux is dehumidified at 380-400° C. for at least 2 hours before use.

9. The use of the high-efficiency submerged arc welding wire suitable for thick plates in marine engineering as claimed in claim 7, characterized in that: The silicon-calcium type sintered flux is TM.SJ55HG flux.

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