SPHEROIDIZATION METHOD OF HIGH CARBON STEEL WIRE MATERIAL, MANUFACTURING METHOD OF STEEL WIRE, MANUFACTURING DEVICE, STEEL WIRE AND TIRE

摘要

PROBLEM TO BE SOLVED: To provide a continuous treatment type spheroidization method capable of softening a high carbon steel wire which is processed harden by cold processing at a low cost and high productivity, and manufacturing a steel wire having high quality such as having a surface quality with less decarbonization or oxidation and excellent in processability.;SOLUTION: A high carbon steel wire material containing carbon of 0.7 to 1.2 mass% is subjected to cold processing with a strain amount in a range of 0.5 to 3.0, then heated at a heating temperature in the range of upper limit T1 calculated by the formula (1): Heating temperature upper limit T1(°C)=-60×ε+780 and a heating temperature lower limit T2 calculated by the formula (2): Heating temperature lower limit T2(°C)=-70×ε+725 for 1 to 10 sec. depending on the added strain amount ε, and then subjected to processing with the strain amount of 0.1 to 1.0 at a temperature in the range of 500 to 700°C.;COPYRIGHT: (C)2014,JPO&INPIT