CO2 gas protection welding process of 800 MPa high-strength steel

Abstract

The invention discloses a CO2 gas protection welding process of 800 MPa high-strength steel. The CO2 protection welding process is characterized by comprising the following steps of: (1) machining a joint: machining an X-shaped groove on the joint; (2) using a solid welding wire with the diameter of 1.2 mm and the tensile strength of 800 MPa, wherein the solid welding wire comprises the following chemical components in percentage by weight: 0.04-0.10% of C, 0.30-0.80% of Si, 1.30-2.0% of Mn, 0.40-1.0% of Ni, 0.20-0.50% of Cr, 0.20-0.60% of Mo, 0.30-0.80% of Cu, 0.05-0.20% of Ti, 0.002-0.010% of B, less than and equal to 0.020% of P, less than and equal to 0.015% of S, less than and equal to 0.03% of Als, and the balance of Fe and inevitable impurities; (3) setting a welding mode: adopting CO2 gas protection welding and a DC power supply opposition method; and (4) welding: carrying out one-side welding with back formation on a first welding line, and then carrying out multilayer multipass welding, wherein interlayer temperature is less than and equal to 160 DEG C. The invention has the advantages of simple process, high operability and low welding energy consumption and welding cost and can be widely used for the technical fields of the gas protection welding of the high-strength steel.

Description

technical field

[0001] The present invention relates to the technical field of high-strength steel gas-shielded welding, in particular to a gas-shielded welding process for high-strength steel, specifically a CO welding method for 800MPa high-strength steel 2 Gas shielded welding process. Background technique

[0002] The use of high-strength steel has many advantages, including weight reduction, cost reduction, and easy processing and transportation. Therefore, high-strength steel is widely used in construction machinery, electric power, pressure vessels, automobiles and other fields. Higher strength and higher toughness and plasticity are important factors to promote the development of high-strength steel. Among them, welding performance is a crucial factor affecting the popularization and application of high-strength steel. Therefore, timely and effective solutions to the weldability of high-strength steel, supporting welding materials and welding processes are conduciv...