Wang Wenxian

Huo Lixing

 Zhang Yufeng

Wang Dongpo

Jing Hongyang

College of Material Science

and Engineering,

Tianjin University,

Tianjin 300072, China

tion of Welded Metal IN control of Welding Distortion Process*

Abstract: Based on the tests of a build-up welding at plate edge (BWPE) and a multi-layer build-up welding on plate (MBWP), the article studies on the solid-state phase transformations which affect welding distortion process and on the influence rule of transformation starting temperature (TST) of welded metal to the welding residual distortion. The welding distortion can be decreased or controlled by the transformation volume expansion caused by solid-state phase transformation of welded metal during the cooling. The test results of BWPE show that when TST is at about 190 ℃, the bending distortion of welded specimen is the smallest, and its displacements at free end are decreased to 58% and 67% compared with those of conventional welding electrodes A102 and E5015, which TST are less than room temperature and equal to 758 ℃ respectively. The test results of MBWP show that when TST were at 100~250 ℃, the welded specimen would appear reversible bending distortion compared with those of A102 and E5015. The maximum deflection value of reversible bending distortion in 8 mm thick plate is –2.94 mm at about 170 ℃ of TST. The test results provide a valuable method to decrease or to control welding residual distortion.

Key words: Solid-state phase transformation  Transformation starting temperature  Welded joint Welding distortion