Cylinder butt joint back-chipping-free weld joint pretreatment process

A cylinder butt joint back-chipping-free weld joint pretreatment process comprises the following steps: before welding, machining a butt joint welding single part; during groove machining, reserving the finish machining allowance; machining and manufacturing a circular fixed supporting base plate, wherein the excircle of the fixed supporting base plate and an inner hole of a butt-joint cylinder welding workpiece are designed according to clearance fit; placing the fixed supporting base plate in a weld joint area in a weldment, enabling two welding workpieces to be aligned, and then enabling the fixed supporting base plate and the two workpieces to be welded and fixed; before the welding of the workpieces, performing the overall groove machining of the weld joint again, and machining the groove form according to the drawing requirements, wherein the depth machining needs to exceed the body thickness of the weldment, and the bottom of a U-shaped welded junction is machined on the fixed supporting base plate and