Abstract
In order to improve the mechanical properties of accelerated cooled TMCP type high strength steel UOE pipe flash butt weldment, reheating and quenching were proposed as a PWHT. Laboratory scale examination was performed, and the following conclusion is obtained.
(1) Significant deterioration in toughness and tensile strength was found in both of TMCP steel weld-line.
(2) After PWHT (reheating and quenching), the tensile strength of flash butt welded joints was restored at the base metals, and no softened region was observed in the welded joints.
(3) The microstructure of flash butt welded joints after PWHT consisted of fine grained ferrite and bainite.
(4) The simulated reheat transition zone showed the good mechanical properties.
The tests results demonstrate that the proposed process is a promising measure to solve the problems of as-welded joints.
