Gas shielded welding process for sulphuric-acid-dew-point-erosion-resistant steel

The invention discloses a gas shielded welding process for sulphuric-acid-dew-point-erosion-resistant steel. The process comprises the following flow processes that base metal is selected, the yield strength ReL of the base metal is 340 to 400MPa, the tensile intensity Rm of the base metal is 440 to 480MPa, the elongation percentage is A25 to 35 percent, the 20-DEG C ballistic work Akv is greater than 100J, and the erosion speed under the conditions of 70 DEG C and 50-percent H2SO4 is lower than 10mg/(cm *h); a gas protection welding wire is selected; a welding groove adopts a V-shaped groove or double-sided V-shaped groove, protection gas is selected, and welding process parameters are set; the welding current is 180 to 220A, the welding speed is 24 to 42 cm/min, and the welding heat input quantity is 8-25kj/cm. The process has the advantages that the anti-corrosion performance of the welding method is effectively improved, the safety of the welding structure is improved, in addition, the process is simple, the welding seam forming effect is good, defects such as air holes and slag clamping cannot be caused, the anti-corrosion performance of welding seams is enhanced, and the welding efficiency is high.