The steel wires for cold heading and cold forging and its production method of possessing the low temperature shocking quality which is superior

摘要

This invention is the steel wires for cold heading and cold forging and something low temperature shocking quality is superior in order where to offer the production method. As for steel wire of this invention, C 0.10 - 0.40wt%, below Si 1.0wt%, Mn 0.30 - 2.0wt%, the or less of P 0.03wt% and below S 0.03wt% are included, the remainder consists of Fe and the impurity. As for the steel wire of this invention, size of the austenite crystal grain is 5 - 20 millimicrons, shocking absorbed energy with the -40C is above 60J/cm2, tensile strength is 70 - 130kgf/mm2. The steel for cold forming of this invention shows markedly high shocking tenacious quality in low temperature of the -40C in comparison with the former spheroidization annealing material and the non quality check steel.