Research of Martensite Bands in the Core of 82B Wires

The character of microstructure in the segregation of 82B wire with two different stelmor control cooling procedures and kinetics of eutectoid transformation of segregation through thermal simulation in the range of 400-600°C were researched. The longitudinal section segregation microstructure and composition were analyzed by OMSEMWDS. The thermal simulation results show that the length of martensite segregation bands is decreased holding 10-40s above 500°C, and martensite band in the core of wire where the content of Mn and Cr elements is higher than matrix because of segregation. Furthermore, Stelmor control cooling experiments in the high speed wire mill confirms that there is a critical temperature500°C to 82B wire above which the eutectoid transformation in the segregation is possible, and enough time above the critical temperature in the Stelmor control cooling lids is the key to optimizing procedure.