Analysis and Solution of Problem about End Defects of SAWH Pipe Made with Two-step Welding Process

The two-step（pre-welding & finish welding） process flow for SAWH pipes is briefed in the paper.Based on the statistic analysis of the pipe end defects，the most serious type among the defects，i.e.，pipe end porosity is qualitatively analyzed. As a result，measures are determined to improve the end quality of the SAWH pipe as made with the two-step welding process. The pipe end porosity defect is obviously reduced，and the pipe end quality improved due to implementation of such measures as grinding butting weld of the run-off tab，and cleaning out the exclusions，etc.