SH-CCT Curves of Low Alloy High Carbon Steel

By measuring the continuous cooling transformation curves in heat affected zone(SH-CCT curves) of two kinds of low alloy high carbon test steels A and B at different cooling speeds in Formastor-D phase transformation tester,combined with metallographic analysis and hardness measurements,SH-CCT curves were obtained.The effect of Ni on the SH-CCT curves was analyzed.The results showed that to ensure the heat affected zone being of pearlite,t8/5 should be longer than 300 s and 200 s respectively in the process of heat treatment after welding of test steel A and B.SH-CCT curves of the test steel B had a separation region between the pearlite transformative and bainite transformative.Ni could postpone the transforming from austenitic to pearlite and bainite,and also lower the tempteratures of Ac3 and Ms.