Effects of carbide-forming elements on the response to thermal treatment of the X45Cr13 martensitic stainless steel

The effects of carbide-forming elements on the response to thermal treatmen t of the X45Cr13 martensitic stainless steel have been investigated. Heat t reatments consisted of austenitizing for 60 s at temperatures ranging from 1000-1250 degrees C. The higher is the solution treatment temperature, the less M23C6 carbide is left out of solution in the austenite. As a result, t he concentration of carbon and alloying elements in the martensite increase s and, therefore, an increase in the hardness until a maximum value of 710 HV was found at austenitizing temperatures of 1120 and 1130 degrees C for t he steels X45Cr13 and X45CrMoV14, respectively. At higher austenitizing tem peratures, the presence of retained austenite was observed, which leads to a lowering of the hardness value. The higher amount of carbide-forming elem ents in the X45CrMoV14 determines an increase in retained austenite from 3 vol % to about 30 vol %. Thus, a drop in the hardness value from 710 to 680 and 585 for the steels X45Cr13 and X45CrMoV14, respectively, was found. (C ) 1998 Kluwer Academic Publishers.