The carburizing temperature of common gear steels is 930 °C
as the carburizing temperature of steel increases to 1 000 ~ 1 050 °C the time of carburization process can be remarkably reduced but it easily leads to grain coarsening. Therefore
the high temperature carburization gear steels are developed by Nb
Ti
B microalloying to fine original austenite grain size in steel. The research progress in gear steels for high temperature carburization at home and abroad including grade and chemical composition
process characteristics
control of structure in high temperature carburized layer and fatigue properties of steel is presented in this article.