ROLLING METHOD FOR ASSEL MILL TO PREVENT CRACKED FLAW

摘要

PROBLEM TO BE SOLVED: To provide a rolling method for an Assel mill which prevents cracked flaws generated in a wall thickness cross section of a steel pipe. SOLUTION: In Assel mill rolling to prevent internal flaws generated in the thick wall cross section of the steel pipe, the rolling method for the Assel mill is to prevent the cracked flaws by controlling the Assel mill drafting of a billet heated to temperatures before piercing at 950-1150°C to be less than 60% of the draft. The prevention of the internal flaws generated in the thick wall cross section of the steel pipe is enabled by controlling the draft at the Assel mill with the draft without reducing productivity by suppressing overheat caused by working heat. COPYRIGHT: (C)2003,JPO