Gas shielded solid welding wire with yield strength of 1300MPa and wire rod
By designing the alloying element factors Sf and Pf, combined with metallurgical process and composition optimization, the gas-shielded solid welding wire and wire rod are prepared, which solves the strength and plasticity problems of existing welding materials in ultra-high-strength steel welding, achieves a balance between high strength and good plasticity, and reduces costs.
Patent Information
- Application Number
- CN202510950244.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-10
- Publication Date
- 2025-09-09
AI Technical Summary
Existing welding materials are difficult to meet the equal strength matching requirements of 1300MPa-grade ultra-high strength steel. There are problems such as the risk of weld yield failure, low welding efficiency and high cost. In addition, the use of high-cost alloy elements in existing welding wires leads to poor weld spread and deterioration of plastic toughness.
The strength factor Sf and plasticity factor Pf related to alloying elements are designed. By controlling the chemical composition and metallurgical process, gas-shielded solid welding wire and wire rod with a yield strength of 1300MPa are prepared. Combined with high-silicon, low-manganese titanium composite deoxidation and heavy rare earth yttrium, the inclusion morphology is optimized, the weld purity and grain refinement are improved, and a balance between strength and plasticity and toughness is achieved.
It achieves equal strength matching with 1300MPa grade ultra-high strength steel, and the weld metal has good plasticity and low-temperature toughness, which reduces the use of high-cost alloy elements and improves the stability and economy of the welding process.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of welding materials, and specifically to a gas-shielded solid welding wire with a yield strength of 1300 MPa and a wire rod used to manufacture the welding wire. The wire is particularly suitable for isobaric matching welding of ultra-high-strength structural steel with a yield strength of 1300 MPa or more and a tensile strength of 1350 MPa or more, and can be widely used in industrial fields such as engineering machinery, coal mining machinery, hydropower equipment, and large-scale buildings. Background Art
[0002] Solid-wire gas metal arc welding is widely used in the manufacture of large structural components due to its advantages, including high welding efficiency, low overall cost, and good process adaptability. With advances in metallurgical technology, the strength grades of structural steel have continued to increase. 1300MPa-grade ultra-high-strength steel has begun to be used in engineering machinery, coal mining machinery, and other fields. Its lightweight properties can reduce material costs and energy consumption, offering significant economic and environmental benefits.
[0003] However, existing welding materials struggle to meet the strength matching requirements of 1300MPa-grade ultra-high-strength steel. Imported low-strength welding wires (such as BOHLER GM120) carry the risk of weld yield failure. Low-hydrogen electrodes are inefficient and costly. Gas-shielded flux-cored or metal-powder-cored wires also face challenges in cost effectiveness. Most patented welding wires have yield strengths in the 1000-1200MPa range, making it difficult to achieve strength matching. The few 1300MPa-grade wires rely on high-cost alloying elements (e.g., nickel content exceeding 6% and molybdenum content exceeding 1%), resulting in high costs, poor weld spread, and reduced ductility and toughness.
[0004] Therefore, the development of a gas-shielded solid welding wire and wire rod with a yield strength of 1300MPa, good plasticity and toughness, and controllable cost has become the key to solving the problem of welding matching of 1300MPa ultra-high strength steel. Summary of the Invention
[0005] The present invention aims to provide a gas-shielded solid welding wire and wire rod with a yield strength of 1300MPa to achieve equal strength matching with 1300MPa ultra-high-strength steel plates, while ensuring that the weld metal has good plasticity (elongation ≥10%) and low-temperature toughness (impact energy ≥27J at -40°C), and reducing the use of high-cost alloying elements to improve economy.
[0006] The present invention achieves a balance between strength and plasticity by designing the alloy element correlation strength factor (Sf) and plasticity factor (Pf). The specific technical solution is as follows: Strength Factor and Plasticity Factor Design Strength factor Sf: It is the comprehensive strengthening effect of carbon, silicon, manganese and other elements. The formula is: Sf = 25[C] + 1.2[Si]+ 2.7[Mn] + 3.3[Cr]+ 1.6[Mo] + 2.2[Cu]+ 320[B] Among them, Sf is controlled between 9.8 and 12.0 to ensure ultra-high strength of the weld metal.
[0007] Plasticity factor Pf: It is the improvement effect of titanium, vanadium, zirconium and other elements on plasticity and toughness. The formula is: Pf = 12[Ti] + 10[V]+ 18[Zr] + 1.2[Mo]+ 0.43[Ni] + 295[B] Among them, Pf≥6.2 to ensure plasticity and toughness under high strength.
[0008] Chemical composition design Based on the above factors, the chemical composition (mass fraction) of welding wire and wire rod is: C: 0.06~0.11%; Si: 0.65~0.95%; Mn: 1.45~1.75%; P: ≤0.008%; S: 0.005~0.010%; Cr: 0.15~0.45%; Mo: 0.40~0.85%; Ni: 1.90~2.85%; Ti: 0. 06~0.14%; V: 0.07~0.25%; Zr: 0.06~0.12%; Cu: 0.15~0.35%; Al: ≤0.004%; B: 0.0020~0.0055%; Y: 0.09~0.30%; O: <0.0035%; N: <0.0055%.
[0009] Design Principles Adopt high silicon, low manganese, titanium composite deoxidation, limit the use of aluminum, combine with heavy rare earth yttrium to optimize inclusion morphology, improve weld purity and refine grains; Through Sf design, the composite strengthening effect of the multi-element alloy is exerted to promote low-temperature phase transformation (lath martensite) and ensure high strength; Through Pf design, strain hardening is reduced, dislocation movement ability is improved, and strength and plasticity and toughness are balanced.
[0010] Beneficial effects of the present invention The yield strength reaches 1300MPa, which can match the strength of 1300MPa ultra-high strength steel and solve the problem of insufficient strength of welded joints; Weld metal elongation ≥10%, -40℃ impact energy ≥27J, overcoming the defect of deterioration of plasticity and toughness of ultra-high strength materials; Reduce the amount of high-cost alloying elements (such as nickel and molybdenum), reduce manufacturing costs, and improve economic efficiency; The welding process has good stability and the weld is evenly formed. It is suitable for argon-rich mixed gas shielded welding and has strong process adaptability. DETAILED DESCRIPTION
[0011] The present invention is further described below by way of specific examples, but is not limited to these examples.
[0012] Chemical compositions of Examples 1 to 5 According to the above chemical composition range, the specific components of Examples 1 to 5 are shown in Table 1, all of which meet Sf=9.8~12.0 and Pf≥6.2.
[0013]
[0014] Preparation process Wire rod preparation: smelt in a vacuum electric furnace according to the above composition, cast and hot-roll into wire rod, and then anneal; Welding wire preparation: The wire rod is drawn, copper-plated, and coiled to make a solid welding wire with a diameter of 1.2 mm.
[0015] Welding performance test Welding parameters were 80% Ar + 20% CO2 shielding gas (flow rate 20 L / min), current 260-280 A, voltage 27-30 V, speed 300 mm / min, and heat input 1.54 kJ / mm. The test results are shown in Table 2.
[0016]
[0017] The results show that Examples 2 and 3 have the best comprehensive performance, with excellent yield strength, plasticity and toughness, and welding formability.
[0018] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A gas shielded solid welding wire with a yield strength of 1300 MPa, characterized in that: The chemical composition by mass fraction is: C: 0.06~0.11%; Si: 0.65~0.95%; Mn: 1.45~1.75%; P: ≤0.008%; S: 0.005~0.010%; Cr: 0.15~0.45%; Mo: 0.40~0.85%; Ni: 1.90~2.85%; Ti: 0.06~0.14%; V: 0.07~0.25%; Zr: 0.06~0.12%; Cu: 0.15~0.35%; Al: ≤0.004%; B: 0.0020~0.0055%; Y: 0.09~0.30%; O: <0.0035%; N: <0.0055%; and satisfy the strength factor Sf=25 [C]+1.2 [Si]+2.7 [Mn]+3.3 [Cr]+1.6 [Mo]+2.2 [Cu]+320 [B], where Sf=9.8~12.0; plasticity factor Pf=12 [Ti]+10 [V]+18 [Zr]+1.2 [Mo]+0.43[Ni]+295 [B], where Pf≥6.
2.
2. A wire rod for manufacturing the welding wire according to claim 1, characterized in that: The chemical composition is the same as that of the welding wire according to claim 1.
3. The welding wire according to claim 1, characterized in that The diameter of the welding wire is 1.2 mm.
4. The welding wire according to claim 1, characterized in that Suitable for argon-rich mixed gas shielded welding, the shielding gas is 80% Ar+20% CO2.
5. The welding wire according to claim 1, characterized in that The yield strength of the weld metal is ≥1300MPa, the tensile strength is ≥1350MPa, the elongation is ≥10%, and the impact energy at -40℃ is ≥27J.