| 摘要 |
PURPOSE:To produce a heat treatment-omission type high tension steel wire or rod having excellent workability by hot working a steel contg. a specific comsn. ratio each of C, Si and Mn then subjecting the steel to adequate cooling to form specific composite structure. CONSTITUTION:A steel contg. 0.05-0.20wt% C, <=1.0% Si, 1.0-2.5% Mn and contg. further >=1 kinds of <=1.0% Cr, <=0.3% Mo or >=1 kinds among <=0.15 Al, <=0.1% Ti and <=0.3% Zr or >=1 kinds of <=0.05% PEM and <=0.003% Ca or <=1.0% Ni is heated to about 900-1,100 deg.C and is hot worked. The steel is thereafter cooled to a temp. range of 300-600 deg.C from 800-950 deg.C at 1-15 deg.C/sec cooling rate to form the composite structure of the low temp. transformation forming phase consisting of 40-75% volume content of ferrite and the balance martensite, bainite or the mixed structure thereof, by which the heat treatment omission type high tension steel wire or rod having excellent workability is obtd. |
