The invention relates to a
welding process for an inner exhaust coil
pipe assembly. The
welding process comprises the following steps of S1, preparing, wherein
grinding and rusting are carried out onthe positions of two annular inner exhaust coil
pipe welding openings before welding; S2, selecting, wherein a 70N rolling welding stick is selected; S3,
spot welding, S4, adding of an inner filling material, wherein after cooling is carried out, circular inner tubes are plugged into the inner walls of the two annular inner exhaust coil
pipe welding openings, and the
diameter of the inner tubes issmaller than the
diameter of inner exhaust coil pipes by 1 mm; S5, welding, wherein the two ends of each of the two inner exhaust coil pipes are clamped through external clamps, then rotation is carried out at the speed being 1 r / min, and electric welding is used for welding the welding openings; S6, cooling, wherein normal temperature
nitrogen at 20 DEG C-30 DEG C is continuously introduced, cooling is carried out, and the inner filling material is taken out; S7,
grinding, wherein a
grinding machine is used for grinding the positions of the welding openings to make the welding positions smooth; and S8, anti-
corrosion treatment, wherein the welding positions are plated with a
metal chromium layer. The method is easy to operate, high in process adaptability and capable of conveniently welding the exhaust coil pipes.