A high-toughness gas-shielded welding wire for welding high-strength steel plates with large input energy

Abstract

The invention relates to a high-toughness gas-shielded welding wire for welding high-strength steel plates with large input energy. The chemical composition and content of the welding wire are: C is 0.02-0.12wt%, Mn is 1.00-2.50wt%, Si is 0.05-0.50wt%, Ti is 0.03-0.30wt%, Zr is 0.03-0.30wt%, B is 0.001-0.004wt%, Cr≤0.50wt%, S≤0.025wt%, P≤0.025wt%, and the balance is Fe and unavoidable impurities. According to the above composition, use converter or electric arc furnace to refine molten iron, or scrap steel, or molten iron and scrap steel after steelmaking, and adjust the composition of molten steel, then cast it into billet, and then hot roll it into wire rod and cold draw it into welding wire according to the conventional process . The invention has the characteristics of simple composition and low cost; the weld metal has good toughness and high tensile strength when welding with the welding material, and is suitable for low-alloy high-strength steel under the condition of large input energy of 100-400kJ / cm welding.

Description

technical field [0001] The invention belongs to the technical field of gas shielded welding wire. In particular, it relates to a high-toughness gas-shielded welding wire for welding high-strength steel plates with large input energy. Background technique [0002] In the past 30 years, in order to improve the welding efficiency of large-scale engineering structures and ensure the safety and reliability of their use, single-side submerged arc welding, gas-electric welding, electroslag welding and other high-energy welding technologies with high welding efficiency have been adopted one after another. The traditional low-alloy high-strength steel has brought new problems, that is, the strength and toughness of the weld and the heat-affected zone (HAZ) of the welded coarse grain are deteriorated, and defects such as welding cold cracks are prone to occur. Therefore, the improvement of weld seam and HAZ toughness has become a hot spot and focus in the research and development of ...

AI Technical Summary

Problems solved by technology

[0005] 1. The content of Si in the welding material is relatively high, because a higher content of Si will promote the formation of M / A and reduce the toughness of the weld and welding heat-affected zone (HAZ);

[0006] 2. The welding material contains one or more of expensive metals such as Ni, Cr, Mo, Cu and other precious alloying elements, which increases the cost of the product;

[0007] 3. The welding material contains rare earth elements. Rare earth elements are very active elements, which are not easy to control, and are easy to pollute the weld metal, which is not conducive to the improvement of the quality of welded joints.

[0008] 4. The welding heat input (or welding line) energy adapted to the welding material is low, less than 100kJ / cm