HIGH STRENGTH WELDED STEEL TUBE HAVING EXCELLENT HYDROGEN EMBRITTLEMENT CRACKING CHRACTERISTIC RESISTANCE OF WELD METAL

摘要

PPROBLEM TO BE SOLVED: To provide a high-strength welded steel tube having excellent welded part hydrogen embrittlement cracking characteristic resistance and a method for manufacturing the same. PSOLUTION: In the method for manufacturing the welded steel tube in which seam welding of a tensile strength of 850 Mpa is performed from an inner surface and an outer surface, then tube expanding or shrinking straightening are performed, the hydrogen concentration of the weld metal preceded on the inner and outer surfaces of the steel tube is 0.2 cc per 100 g at ordinary temperature before the straightening and the hydrogen concentration of the preceded weld metal is 0.2 cc per 100 g at ordinary temperature. PCOPYRIGHT: (C)2007,JPO&INPIT