STEEL FOR HIGH STRENGTH STEEL WIRE ROD EXCELLENT IN COLD-WIRE DRAWABILITY AND HIGH STRENGTH STEEL WIRE ROD OBTAINED BY USING THIS, AND PRODUCING METHOD OF THEM

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a high strength steel wire rod excellent in a cold-wire drawability.;SOLUTION: When the steel for high strength steel wire rod satisfying a regulated component composition is produced, as the inner wall material in a ladle used after secondary refining, alumina-base material is used and according to [C](mass%) that means the C content in the steel, the operation is performed under the following conditions. (1) In the case of 0.7%≤[C]0.8%, slag-off operation is performed before the secondary refining so that the slag amount is reduced to≤7.5kg/t. (2) In the case of 0.8%≤[C]0.9%, the ladle in which the type of steel received at the last time is [Al]≤0.015%, is used and the slag-off operation is performed before the secondary refining so that the slag amount is reduce to ≤1.5kg/t. (3) In the case of 0.9%≤[C]≤1.0%, the ladle in which the receiving steel is at a first time or the steel at the last time is the same type of steel, is used and the slag-off operation is performed before the secondary refining so that the slag amount is reduced to ≤1.5kg/t and slag basicity after the secondary refining, is 1-2.;COPYRIGHT: (C)2004,JPO