Submerged arc welding wire for X65 hydrogen transmission pipeline steel

Abstract

The invention relates to the technical field of submerged arc welding wires, in particular to a submerged arc welding wire for X65 hydrogen transmission pipeline steel. A conventional submerged arc welding wire for X65 pipeline steel pipe welding is poor in mechanical property and hydrogen resistance of deposited metal of an obtained welding seam under the high heat input welding condition. In order to solve the technical problems, the submerged arc welding wire for the X65 hydrogen transmission pipeline steel is provided, a proper amount of Ni, V, Ti, Nb and Ce elements are further added in the chemical components of the submerged arc welding wire besides C, Mn, Si, Fe and other basic elements, the obtained submerged arc welding wire is suitable for X65 hydrogen transmission pipeline steel pipe welding, and a welded joint has good mechanical property and hydrogen resistance.

Description

Technical Field

[0001] The invention relates to the technical field of submerged arc welding wires, and in particular to a submerged arc welding wire for X65 hydrogen transmission pipeline steel. Background Art

[0002] The hydrogen transportation system is the link between hydrogen production and consumption, and is also a key part of developing a large-scale hydrogen economy. Over long distances and in large volumes, transporting hydrogen by pipeline offers greater economic advantages than other transportation methods, such as hydrogen trailers and liquid hydrogen transport. However, hydrogen pipeline steel faces the problem of "hydrogen embrittlement" during service. During hydrogen transportation, hydrogen dissolves in atomic or ionic form in the structural defects of the pipeline steel and continuously accumulates, causing bubbling on the surface of the pipeline steel or cracks to form inside. In addition, when hydrogen molecules accumulate at dislocations and tiny gaps and reach a supersaturated state, they reduce the plasticity of the pipeline steel. X65 pipeline steel has a low sensitivity to hydrogen embrittlement and is suitable for hydrogen transportation.

[0003] Chinese invention patent CN 117900693 A discloses a welding wire for submerged arc welding of hydrogen-resistant pipeline steel. The chemical composition of the welding wire is designed with a low Mn, high Mo, and Ni alloy. The welding wire is mainly suitable for submerged arc welding of hydrogen-resistant pipeline steel below L360 / X52 steel grades, and cannot meet the welding requirements of L450 / X65 hydrogen pipeline steel grades.

[0004] Chinese invention patent CN 115673599 A discloses a high-crack-arrest, acid-resistant submerged arc welding wire for X65 pipeline steel. The wire is matched with the basic sintered flux SJ101G and welded using a four-wire submerged arc welding process. Experiments were conducted on X65 (19.8mm wall thickness) pipeline steel plates. After welding, the X65 pipeline steel plate welded joints exhibited excellent mechanical properties, resistance to hydrogen-induced cracking (HIC), and resistance to sulfide stress corrosion (SSCC). However, the submerged arc welding wire described in this patent is not suitable for welding hydrogen pipeline steel, and the patent does not evaluate the performance of X65 pipeline steel pipe welded joints. The geometry, stress state, residual stress, and service conditions of pipe welds differ significantly from those of plate welds. The performance of plate welded joints cannot be representative of pipe welded joints.

[0005] In summary, there is relatively little research on high-energy-input welding of X65 pipeline steel pipes in the existing technology. Research and development of submerged arc welding wire suitable for high-energy-input welding of X65 pipeline steel pipes and fluxes matching the submerged arc welding wires have important theoretical value and practical significance. Summary of the Invention

[0006] A problem in the prior art is that conventional submerged arc welding wire used for welding X65 pipeline steel pipes suffers from poor mechanical properties and hydrogen resistance in the weld metal obtained under high-heat input welding conditions. To address this technical problem, the present invention provides a submerged arc welding wire for X65 hydrogen pipeline steel. The chemical composition of the submerged arc welding wire is free of the metallic elements Cu, Al, Cr, the non-metallic element B, or the rare earth element Y. The chemical composition of the submerged arc welding wire, measured by mass percentage, comprises the following components:

[0007] C: 0.06-0.09%; Mn: 1.3-1.6%; Si: 0.10-0.50%; P≤0.005%; S≤0.005%; Ni: 0.50-1.2%;

[0008] Mo: 0.05-0.25%; V ≤ 0.03% and not 0; Ti: 0.04-0.08%; Nb ≤ 0.15% and not 0; Ce: 0.01-0.05%; the balance being Fe and unavoidable impurities.

[0009] Preferably, the mass percentage of Mn in the chemical composition of the submerged arc welding wire is 1.36-1.52%.

[0010] Preferably, the mass percentage of Si in the chemical composition of the submerged arc welding wire is 0.28-0.41%.

[0011] Preferably, the mass percentage of Ni in the chemical composition of the submerged arc welding wire is 0.73-1.15%.

[0012] Preferably, the mass percentage of Mo in the chemical composition of the submerged arc welding wire is 0.11-0.18%.

[0013] Preferably, the mass percentage of V in the chemical composition of the submerged arc welding wire is 0.015-0.022%.

[0014] Preferably, the mass percentage of Ti in the chemical composition of the submerged arc welding wire is 0.05-0.07%.

[0015] Preferably, the mass percentage of Nb in the chemical composition of the submerged arc welding wire is 0.07-0.11%.

[0016] Preferably, the mass percentage of Ce in the chemical composition of the submerged arc welding wire is 0.018-0.032%.

[0017] The present invention provides a submerged arc welding wire for X65 hydrogen pipeline steel, the composition design ideas of which are as follows:

[0018] (1) C is the main strengthening element in the weld structure. The welding wire of the present invention preferably controls the C content below 0.15%, preferably 0.06-0.09%.

[0019] (2) Mn is a good deoxidizer and solid solution strengthening element, which can improve the strength and low-temperature impact toughness of the weld metal. The welding wire of the present invention needs to control the Mn content between 1.3% and 1.6%.

[0020] (3) Si plays a major role in deoxidation and strengthening in the weld metal, significantly improving the impact toughness and corrosion resistance of the weld. However, too high a Si content will lead to excessive segregation of P at the grain boundaries. The welding wire of the present invention needs to control the Si content between 0.10% and 0.50%.

[0021] (4) As impurity elements, the lower the content of P and S, the better. The hydrogen corrosion resistant welding wire requires the lower the content of P and S elements, the better. The welding wire of the present invention preferably controls the P content to below 0.005% and the S content to below 0.005%.

[0022] (5) Ni can reduce the low-temperature brittle transition temperature of the weld metal while maintaining good plasticity and toughness. Introducing Ni into the weld is beneficial to improving the repulsion force of weld fatigue and the low-temperature brittle transition temperature. The Ni content in the submerged arc welding wire of the present invention is preferably controlled between 0.5-1.2%.

[0023] (6) Mo can effectively prevent the precipitation and growth of ferrite, promote the formation of high dislocation density acicular ferrite AF, thereby improving toughness. However, when the Mo content is high, more martensite and austenite (MA) components will be produced, weakening the plasticity and toughness of the weld metal. The present invention controls the Mo content of the welding wire to be between 0.05-0.25%.

[0024] (7) Ti is suitable for high-energy submerged arc welding of straight seam hydrogen pipeline steel. Ti has a good toughening effect and can form very fine dispersions in the weld, effectively preventing grain growth and becoming the nucleation core of acicular ferrite, which is beneficial to improving the toughness of the weld. The welding wire of the present invention preferably controls the Ti content between 0.04% and 0.08%.

[0025] (8) V can form nano-scale vanadium carbides, increase effective hydrogen traps, and reduce the hydrogen diffusion coefficient. The V content in this welding wire is preferably controlled below 0.03%;

[0026] (9) Nb helps to increase the content of acicular ferrite and fine granular bainitic ferrite in the weld, which can enhance the strength and toughness of the weld metal. After adding Nb, the nano-sized niobium carbides formed in the weld deposited metal can delay the formation of hydrogen-induced bubbles. The Nb content of this welding wire needs to be controlled below 0.15%.

[0027] (10) The rare earth element Ce can improve the strength, plasticity and toughness of the weld metal. Ce can play a role in desulfurization and deoxidation. During the welding process, Ce will preferentially react with the sulfur and oxygen in the metal to generate impurities that overflow into the weld, thereby improving the weld performance. The Nb content in this welding wire is preferably controlled between 0.01-0.05%.

[0028] The present invention has the following beneficial effects:

[0029] (1) The present invention provides a submerged arc welding wire for X65 hydrogen pipeline steel. The chemical composition of the submerged arc welding wire does not contain Cu, Al, Cr, B, and Y. In addition to the basic elements such as C, Mn, Si, and Fe, the chemical composition also contains appropriate amounts of Ni, V, Ti, Nb, and Ce. The obtained submerged arc welding wire is suitable for high-energy-input welding of X65 hydrogen pipeline steel pipes, and the welded joint has high impact toughness at -20°C.

[0030] (2) The present invention provides a submerged arc welding wire for X65 hydrogen pipeline steel. The submerged arc welding wire is equipped with a basic flux SJ101MH. The weld joint has good HIC resistance and slow strain rate tensile performance under hydrogen environment, and has good hydrogen resistance, meeting the service requirements of the X65 hydrogen pipeline. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the following examples. However, it should be understood that the following examples are merely illustrative of the embodiments of the present invention and are not intended to limit the scope of the present invention.

[0032] Example 1

[0033] A submerged arc welding wire for X65 hydrogen pipeline steel, the chemical composition of which is calculated by mass percentage, and the element composition is as follows:

[0034] C: 0.09%; Mn: 1.41%; Si: 0.39%; P: 0.005%; S: 0.003%; Ni: 0.73%; Mo: 0.15%; V: 0.016%; Ti: 0.06%; Nb: 0.08%; Ce: 0.018%; the balance is Fe and inevitable impurities.

[0035] Example 2

[0036] A submerged arc welding wire for X65 hydrogen pipeline steel, the chemical composition of which is calculated by mass percentage, and the element composition is as follows:

[0037] C: 0.06%; Mn: 1.36%; Si: 0.28%; P: 0.005%; S: 0.002%; Ni: 1.15%; Mo: 0.12%; V: 0.019%; Ti: 0.05%; Nb: 0.11%; Ce: 0.021%; the balance is Fe and inevitable impurities.

[0038] Example 3

[0039] A submerged arc welding wire for X65 hydrogen pipeline steel, the chemical composition of which is calculated by mass percentage, and the element composition is as follows:

[0040] C: 0.07%; Mn: 1.48%; Si: 0.32%; P: 0.005%; S: 0.002%; Ni: 0.84%; Mo: 0.16%; V: 0.017%; Ti: 0.05%; Nb: 0.07%; Ce: 0.022%; the balance is Fe and inevitable impurities.

[0041] Example 4

[0042] A submerged arc welding wire for X65 hydrogen pipeline steel, the chemical composition of which is calculated by mass percentage, and the element composition is as follows:

[0043] C: 0.06%; Mn: 1.52%; Si: 0.37%; P: 0.005%; S: 0.002%; Ni: 0.92%; Mo: 0.11%; V: 0.022%; Ti: 0.06%; Nb: 0.07%; Ce: 0.032%; the balance is Fe and inevitable impurities.

[0044] Example 5

[0045] A submerged arc welding wire for X65 hydrogen pipeline steel, the chemical composition of which is calculated by mass percentage, and the element composition is as follows:

[0046] C: 0.08%; Mn: 1.39%; Si: 0.41%; P: 0.004%; S: 0.003%; Ni: 0.95%; Mo: 0.18%; V: 0.015%; Ti: 0.07%; Nb: 0.11%; Ce: 0.026%; the balance is Fe and inevitable impurities.

[0047] Comparative Example 1 is the same as Example 4, except that the element Nb is not added to the chemical composition of the submerged arc welding wire of Comparative Example 1.

[0048] Comparative Example 2 is the same as Example 4, except that the element Ce is not added to the chemical composition of the submerged arc welding wire in Comparative Example 2.

[0049] Comparative Example 3 is the same as Example 4, except that element V is not added to the chemical composition of the submerged arc welding wire in Comparative Example 3.

[0050] Comparative Example 4 is the same as Example 4, except that the element Ti is not added to the chemical composition of the submerged arc welding wire of Comparative Example 4.

[0051] Comparative Example 5 is the same as Example 4, except that the element Ni is not added to the chemical composition of the submerged arc welding wire of Comparative Example 5.

[0052] Comparative Example 6 is the same as Example 4, except that the element Mo is not added to the chemical composition of the submerged arc welding wire of Comparative Example 6.

[0053] Comparative Example 7 is the same as Example 4, except that the mass percentage of C in the chemical composition of the submerged arc welding wire of Comparative Example 7 is 0.03%.

[0054] Comparative Example 8 is the same as Example 4, except that the mass percentage of Ti in the chemical composition of the submerged arc welding wire of Comparative Example 8 is 0.02%.

[0055] Comparative Example 9 is the same as Example 4, except that the mass percentage of Ti in the chemical composition of the submerged arc welding wire of Comparative Example 9 is 0.15%.

[0056] Comparative Example 10 is the same as Example 4, except that the mass percentage of Ni in the chemical composition of the submerged arc welding wire of Comparative Example 10 is 0.3%.

[0057] Comparative Example 11 is the same as Example 4, except that the mass percentage of Mo in the chemical composition of the submerged arc welding wire of Comparative Example 11 is 0.3%.

[0058] Comparative Example 12 is the same as Example 4, except that the chemical composition of the submerged arc welding wire of Comparative Example 12 further contains the metal element Al, and the mass percentage of Al is 0.055%.

[0059] Comparative Example 13 is the same as Example 4, except that the chemical composition of the submerged arc welding wire of Comparative Example 13 further contains the metal element Cr, and the mass percentage of Cr is 0.1%.

[0060] Comparative Example 14 is the same as Example 4, except that the chemical composition of the submerged arc welding wire of Comparative Example 14 further contains metal element B, and the mass percentage of B is 0.001%.

[0061] Comparative Example 15 is the same as Example 4, except that the chemical composition of the submerged arc welding wire of Comparative Example 15 further contains the metal element Cu, and the mass percentage of Cu is 0.25%.

[0062] Comparative Example 16 is the same as Example 4, except that the mass percentage of V in the chemical composition of the submerged arc welding wire of Comparative Example 16 is 0.06%.

[0063] Comparative Example 17 is the same as Example 4, except that the rare earth element Y is used in Comparative Example 17 to replace the element Ce in the chemical composition of the submerged arc welding wire in Example 4.

[0064] According to the chemical composition formula of the submerged arc welding wire in the above Examples 1-5 and Comparative Examples 1-17 of the present invention and the conventional welding material production process, the raw welding material is obtained after desulfurization and dephosphorization of molten iron, converter smelting, molten steel refining outside the furnace, continuous casting, high-speed wire, and wire rolling. The raw welding material is then mechanically shelled, drawn, copper-plated, and layer-wound to obtain a submerged arc welding wire with a diameter of Φ = 4.0 mm. The raw welding material is then mechanically shelled, drawn, copper-plated, and layer-wound in the conventional welding wire production process to obtain the required submerged arc welding wire sample.

[0065] Under the same welding process conditions, the submerged arc welding wires obtained in the embodiments of the present invention and the comparative example were combined with the basic sintered flux SJ101MH to perform high-heat input three-wire submerged arc welding on a straight seam pipe with a diameter of Φ = 610 mm. The basic sintered flux SJ101MH consists of 25% SiO2, 21% CaF2, 22% CaO, 21% MgO, and 11% MnO by mass. The three-wire submerged arc welding high-heat input welding process uses internal and external welding. The internal welding process is the same as the external welding process. The current for the first wire is 1050A and the voltage is 35V; the current for the second wire is 820A and the voltage is 40V; the current for the third wire is 720A and the voltage is 41V. The welding speed is 1.5m / min.

[0066] Comparative Example 18 is the same as Example 4, except that the flux used in Comparative Example 18 is alkaline flux SJ101G.

[0067] Performance Testing

[0068] (1) Relevant performance tests were performed on the welded joints formed by submerged arc welding of three straight seam pipes according to the embodiment of the present invention and the comparative example. Hardness test, tensile test, impact test and bending test were respectively carried out in accordance with the following standards: hardness test: GB / T 231.1-2018 "Brinell hardness test for metallic materials - Part 1: Test method", tensile test: test standard GB / T 228.1 "Metallic materials - Tensile test - Part 1: Room temperature test method", impact test: test standard GB / T 229 "Metallic materials - Charpy pendulum impact test method", bending test: test standard GB / T 232 "Metallic materials - Bend test method". The test results are shown in Table 1 and Table 1.

[0069] Table 1

[0070]

[0071] Table 1

[0072]

[0073] It can be seen from Table 1 and Table 1 that the submerged arc welding wire for X65 hydrogen pipeline steel of the present invention has excellent tensile properties and impact toughness, with a tensile strength of more than 590 MPa and a yield strength of more than 470 MPa; at the same time, the submerged arc welding wire has excellent impact toughness, with an impact energy of ≥180 J at -20°C. Compared with comparative examples 1-17, the strength and toughness are well matched, and can fully meet the welding requirements of the X65 hydrogen pipeline.

[0074] (2) The welded joints formed by three-wire submerged arc welding of straight seam pipes (Φ=610 mm) in the embodiment of the present invention and the comparative example were tested for HIC resistance in accordance with GB / T 8650, "Method for Assessing Resistance of Pipeline Steel and Pressure Vessel Steel to Hydrogen Induced Cracking." The test results are shown in Table 2. The test results show that in the HIC resistance test, the CLR, CTR, and CSR test results of the welded joints were all 0. The specific test results are shown in Table 2 and Table 2.

[0075] Table 2

[0076] Test items CLR (%) CTR (%) CSR (%) Macrometallography Example 1 0 0 0 No cracking Example 2 0 0 0 No cracking Example 3 0 0 0 No cracking Example 4 0 0 0 No cracking Example 5 0 0 0 No cracking Comparative Example 1 0 0 0 No cracking Comparative Example 2 0 0 0 No cracking Comparative Example 3 3 1.2 0.2 Cracks Comparative Example 4 2 0.9 0.2 Cracks Comparative Example 5 1.6 0.8 0.2 Cracks Comparative Example 6 0 0 0 No cracking Comparative Example 7 0 0 0 No cracking Comparative Example 8 0 0 0 No cracking Comparative Example 9 0 0 0 No cracking Comparative Example 10 1.4 0.9 0.2 Cracks Comparative Example 11 0 0 0 No cracking Comparative Example 12 0 0 0 No cracking Comparative Example 13 0 0 0 No cracking Comparative Example 14 0 0 0 No cracking Comparative Example 15 0 0 0 No cracking Comparative Example 16 1 0.9 0.1 Cracks

[0077] Table 2

[0078] Test items CLR (%) CTR (%) CSR (%) Macrometallography Comparative Example 17 0 0 0 No cracking Comparative Example 18 0 0 0 No cracking

[0079] It can be seen from Table 2 and Table 2 that Examples 1-5 of the submerged arc welding wire for X65 hydrogen pipeline steel of the present invention not only have excellent strength and toughness, but also have excellent hydrogen resistance. In the hydrogen induced cracking (HIC) test, CLR, CTR, and CSR are all 0, and no cracks are generated in the macroscopic metallographic structure. In Comparative Examples 1-17, some macroscopic metallographic structures have cracks.

[0080] (3) The welded joints formed by three-wire submerged arc welding of straight seam pipes (Φ=610 mm) in the embodiment of the present invention and the comparative example were subjected to slow tensile tests according to GB / T 34542-2018 “Test method for compatibility of metallic materials with hydrogen environment”. The test results were as follows: -5 / S conditions, the loss rate of strength, elongation and cross-sectional shrinkage of welded joints in hydrogen environment relative to nitrogen environment.

[0081] Table 3, continued Table 3 The examples and comparative examples were tested at a pressure of 10 MPa and a strain rate of 1×10 -5Under / S conditions, the loss rate of strength, elongation and cross-sectional shrinkage of welded joints in hydrogen environment relative to nitrogen environment.

[0082] The calculation formula of the strength loss rate is: (tensile strength of the welded joint in a nitrogen environment - tensile strength of the welded joint in a hydrogen environment) / tensile strength of the welded joint in a nitrogen environment × 100%.

[0083] The calculation formula of the elongation loss rate is: (elongation of the weld joint in a nitrogen environment-elongation of the weld joint in a hydrogen environment) / elongation of the weld joint in a nitrogen environment×100%.

[0084] The calculation formula for the section shrinkage loss rate is: (section shrinkage of the welded joint in a nitrogen environment - section shrinkage of the welded joint in a hydrogen environment) / section shrinkage of the welded joint in a nitrogen environment × 100%.

[0085] Table 3

[0086] Test items Tensile strength loss rate Elongation loss rate Sectional shrinkage loss rate Example 1 0.3％ 36.2％ 31.8％ Example 2 0.5％ 32.7％ 27.4％ Example 3 0.9％ 33.6％ 29.9％ Example 4 1.1％ 34.5％ 34.6％ Example 5 0.8％ 32.9％ 32.5％ Comparative Example 1 2.8％ 43.2％ 44.6％ Comparative Example 2 1.4％ 45.8％ 36.7％

[0087] Table 3

[0088] Test items Tensile strength loss rate Elongation loss rate Sectional shrinkage loss rate Comparative Example 3 1.8％ 45.3％ 42.6％ Comparative Example 4 3.2％ 44.6％ 42.3％ Comparative Example 5 2.9％ 48.3％ 45.4％ Comparative Example 6 1.6％ 42.6％ 33.5％ Comparative Example 7 2.6％ 35.6％ 36.7％ Comparative Example 8 1.8％ 36.8％ 39.2％ Comparative Example 9 1.6％ 41.2％ 39.8％ Comparative Example 10 3.1％ 46.2％ 45.3％ Comparative Example 11 1.9％ 42.5％ 43.8％ Comparative Example 12 1.6％ 38.2％ 41.6％ Comparative Example 13 2.6％ 43.1％ 42.1％ Comparative Example 14 1.2％ 35.8％ 37.2％ Comparative Example 15 1.3％ 37.7％ 37.9％ Comparative Example 16 2.7％ 38.9％ 39.6％ Comparative Example 17 1.3％ 37.4％ 36.7％ Comparative Example 18 1.4％ 42.2％ 39.8％

[0089] It can be seen from Table 3 and Table 3 that the submerged arc welding wires for X65 hydrogen pipeline steel of the present invention in Examples 1-5 are as follows: -5 Under the conditions of 1 / S, the strength loss of the welded joint in a hydrogen environment was ≤1.5% relative to that in a nitrogen environment, and both the reduction in area and the elongation loss were ≤40%, demonstrating good hydrogen resistance. The welded joints in Comparative Examples 1-17 exhibited greater strength loss, reduction in area, and elongation loss in a hydrogen environment relative to that in a nitrogen environment.

[0090] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A submerged arc welding wire for X65 hydrogen pipeline steel, characterized in that: The chemical composition of submerged arc welding wire is calculated by mass percentage and includes the following components: C: 0.06-0.09%; Mn: 1.3-1.6%; Si: 0.10-0.50%; P≤0.008%; S≤0.005%; Ni: 0.50-1.2%; Mo: 0.05-0.25%; V ≤ 0.03% and not 0; Ti :0.04-0.08%; Nb≤0.15% and not 0; Ce: 0.01-0.05%; The balance is Fe and inevitable impurities.

2. The submerged arc welding wire for X65 hydrogen pipeline steel according to claim 1, characterized in that: The mass percentage of Mn in the chemical composition of submerged arc welding wire is 1.36-1.52%.

3. The submerged arc welding wire for X65 hydrogen pipeline steel according to claim 1, characterized in that: The mass percentage of Si in the chemical composition of submerged arc welding wire is 0.28-0.41%.

4. The submerged arc welding wire for X65 hydrogen pipeline steel according to claim 1, characterized in that: The mass percentage of Ni in the chemical composition of the submerged arc welding wire is 0.73-1.15%.

5. The submerged arc welding wire for X65 hydrogen pipeline steel according to claim 1, characterized in that: The mass percentage of Mo in the chemical composition of the submerged arc welding wire is 0.11-0.18%.

6. The submerged arc welding wire for X65 hydrogen pipeline steel according to claim 1, characterized in that: The mass percentage of V in the chemical composition of the submerged arc welding wire is 0.015-0.022%.

7. The submerged arc welding wire for X65 hydrogen pipeline steel according to claim 1, characterized in that: The mass percentage of Ti in the chemical composition of the submerged arc welding wire is 0.05-0.07%.

8. The submerged arc welding wire for X65 hydrogen pipeline steel according to claim 1, characterized in that: The mass percentage of Nb in the chemical composition of the submerged arc welding wire is 0.07-0.11%.

9. The submerged arc welding wire for X65 hydrogen pipeline steel according to claim 1, characterized in that: The mass percentage of Ce in the chemical composition of the submerged arc welding wire is 0.018-0.032%.

10. A submerged arc welding method for X65 hydrogen pipeline steel, characterized in that: The submerged arc welding wire obtained according to any one of claims 1 to 9 is used as welding wire, and the basic flux SJ101MH is used as welding flux.

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