The invention relates to the technical field of
welding, in particular to a crack-free efficient
welding method for a
butt joint of a large and thick high-strength steel plate, which comprises the following steps: firstly, forming a
welding groove of the large and thick high-strength steel plate into an inverted trapezoidal structure at the upper part and a large truncated
edge structure at the lower part; a base plate and an
electric heating plate are arranged on the back face of the
butt joint gap of the high-strength steel large
thick plate; then, the pre-welding
assembly gap of the high-strength steel large
thick plate is set, and positioned welding is conducted on the four corners of the
butt joint gap; then backing welding is conducted on the large truncated
edge structure area of the high-strength steel large
thick plate; and finally, filling welding and cosmetic welding are carried out on the inverted trapezoidal structure area of the high-strength steel large thick plate, a new welding method is adopted by optimizing the groove form, the welding line cladding
metal filling amount is reduced, the welding efficiency is improved, the welding heat input is reduced, welding angle deformation is reduced, and the welding quality is improved through the groove of the inverted trapezoidal large truncated edge,
laser welding bottoming and
laser wire filling welding filling. And after-welding
slow cooling is achieved, the welding pass can be obviously reduced, the welding efficiency is improved, the joint strength is improved, and the welding quality is guaranteed.