Method for producing ultrafine wire of austenitic stainless steel and ultrafine wire

摘要

PURPOSE:To improve workability and to produce an extra fine wire having high strength and excellent in settling resistance by regulating the contents of Al, S, and O in a steel composition so that they satisfy specific relations, performing wiredrawing, and subjecting to heat treatment under specific conditions. CONSTITUTION:In a wire rod for producing extra fine wire of austenitic stainless steel, S, Al, and O are incorporated, by weight, =0.005%, =0.005%, and =0.005%, respectively, into a steel composition. Further, the relation between S and Al satisfies the condition of an equality S=Al/2 and a structure where the composition of the nonmetallic inclusions in the steel consists of oxysulfide containing, in total, =1wt.% S is formed. This stainless steel is subjected to wire rod rolling and to a repetition of annealing and wiredrawing, by which an extra fine wire is produced. Successively, at the time of performing heat treatment, wiredrawing before heating is made at =50% and successive heat treatment is performed at 100-600 deg.C under the condition where the value of (k) represented by k=TX(logt+20)X10-8 satisfies =6.5.