Process for producing steel bar wire rod for cold working.

摘要

A steel comprising 0.1 to 1.5% of C and 0.25 to 2.0% of Mn is heated to 900 to 1250 DEG C, and the heated steel is hot-rolled at a temperature in the range of from Ar3 to (Ar3 + 200) DEG C or Arcm to (Arcm + 200) DEG C with a total reduction of area of 30% or more. The hot-rolled material is cooled to complete a ferrite/pearlite transformation or a pro-eutectoid cementite/pearlite transformation. The transformed material is subjected to finish hot rolling at a temperature in the range of from (Ac1 - 400) to Ac1 DEG C with a total reduction ratio of 10 to 70%. If necessary, the material after the finish hot rolling is cooled to 300 DEG C at an average cooling rate of 1 DEG C/sec or less. A spheroidization annealing of the steel bar wire rod produced according to the process of the present invention enables a good spheroidized texture to be formed.