continuous casting method of 13Cr seamless steel pipe for a round slab

摘要

PROBLEM TO BE SOLVED: To provide a continuous casting method of a round strand for a 13Cr seamless steel pipe which can inhibit generation of a straight line crack and sufficiently inhibit, at practical level, the generation of an axis crack, in particular, a shrinkage porosity generated at the final stage of solidification and an A-type crack due to the shrinkage porosity.;SOLUTION: In continuous casting of the round strand for the 13Cr seamless steel pipe, secondary cooling with water cooling is stopped when a solid phase ratio at a position at a distance of 15 mm in a radial direction from an axis of the strand is 0.03-0.1, and thereafter only cooling with radiation heat transfer is continued to completely solidify the inside of the strand.;COPYRIGHT: (C)2013,JPO&INPIT