Acid-proof X70MS steel-grade spiral welded pipe and manufacturing method thereof

The invention discloses an acid-proof X70MS steel-grade spiral welded pipe and a manufacturing method thereof. The spiral welded pipe is made of X70MS steel-grade plate coils. The processing process for the spiral welded pipe comprises the following steps of: uncoiling, flattening, milling edges, prebending, molding, internally welding, externally welding, expanding the end of the pipe, performing laminated ultrasonic inspection on a base material, performing X-ray inspection on welding seams, performing a hydrostatic test, performing ultrasonic inspection on the welding seams, chamfering theend of the pipe and inspecting a finished product. The X70MS steel-grade spiral seam submerged-arc welding pipe has high intensity and high acid resistance and is suitable for conveying acid oil gas media.