Residual Magnetism Characteristics of HSAW Pipe and Relevant Reduction Measures

Addressing the residual magnetism phenomenon as occurring at the pipe end during manufacturing process of HSAW pipe， an analysis is conducted on the magnetism mechanism and the causes for development of the residual magnetism. Also studied here in the paper are common residual magnetism characteristics of the steel pipe. To control the residual magnetism，the wiring scheme for optimizing the welding system and implementing of off-line AC and DC current degaussing measures are proposed as per the size，polarity and distribution of the residual magnetism in a bid to meet the requirements for residual magnetism inspection as specified under application standard，and improve weld pipe quality.