Continuous-cooling Transformation Diagrams For Continuous Casting 945 Steel And Its Application

Continuous-cooling transformation diagrams for continuous casting 945 steel have been measured at a series of austenitized temperatures with the dilatometer. The effect of austenitized temperature and alloying elements on Ms (Martensite starting point), shape and location of CCT diagrams, Bainite and Pearlite transformation was discussed .The law of CCT curve forming at various austenitized temperatures was investigated. The relation between formation of different phase and austenitized temperature, critical cooling-rate and austenitized temperature has been studied. The structure of the specimens treated for measuring CCT diagrams, as well as microhardness, was analyzed .The results show that Ms would not be related to austenitized temperature at a temperature above Ac3 line, but it will decrease with increase in austenitized temperature at the two-phase field and that decreasing with austenitized temperature, gestational period of Ferrite and Bainite will to be shorter and critical cooling-rate will to be rapider. In this case Martensite field removes from Bainite field, but Bainite field removes from Ferrite field when specimens were austenitized at 1300℃.