Abstract: The effects of heat treatment process on microstructure and mechanical properties of 10CrNiMoV bulb flat steel were studied by optical microscopy, SEM, TEM and so on. The results show that a large number of granular bainite were formed in the period of rolling or normalizing continuous cooling, which decreased obviously the low temperature toughness of the steel. The granular bainite could be decomposed by direct tempering treatment after hot rolling and the toughness of steel could be improved, the Akv-40 value could be reach to 46J. Furthermore, Akv-40 could be raised up to 144J by normalizing and tempering treatment because of the granular bainite decomposed sufficiently.
Authors: Chen Xuehui, Yang Caifu, Chai Feng, Zhang Qian, Hou Yaqing, and Yang Li
Keywords: 10CrNiMoV bulb flat steel, Heat treatment, Granular bainite, Low-temperature toughness