The Measurement and Control of Residual Stress in Spiral Sub-Merged Arc Welded Pipe

The problems related to the measurement and control of residual stress in the production of SSAW pipe are analyzed based on tests: (1) The relationship between circumferential opening in cut-ring test and residual stress from mechanical cutting stress releasing test; (2) The effects of severing position on the measured opening; (3) The effects of hydrostatic test on residual stress of SSAW pipe; (4) The supplementary specification of SSAW pipe. It is put forward that the circumferential opening varies with the severing position, and the normal hydrostatic test mainly bring about the redistribution of the residual stress as well as the decrease of that. The appropriate higher pressure can reduce residual stress considerably. Some suggestions about the supplementary specification related to residual stress of SSAW pipe were brought forward.