| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preventing cracking in the corner part of a bloom generated in the hot-rolling of the bloom thereafter even if the staying time in a heating furnace for heating the bloom exceeds 3.5 hr, when the bloom of a 18-8 based stainless steel containing Ca is hot-rolled. SOLUTION: When the staying time for heating the bloom in the heating furnace exceeds 3.5 hr, in order to hot-roll the bloom of the 18-8 based stainless steel containing Ca, the preventive method of the generation of the crack flaw shown in the attached Figure 1 at the hot-rolling of the bloom is performed as the followings: in the heating furnace composed of a pre-heating zone, a heating zone and a soaking zone, the setting temperatures of the heating zone and the soaking zone are respectively made to lower by 10°C than the setting temperatures, when the furnace-staying time is <3.5 hr, to control to lower by 10°C hot-rolling temperature of the bloom, in order to perform hot-rolling so that the generating quantity of ferrite at the corner part of the bloom is restrained. COPYRIGHT: (C)2009,JPO&INPIT
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