Improvement of mechanical properties of high strength low-alloyed steel by unconventional heat treatment

Abstract

Modern steels processed using unconventional he at treatments can reach substantially better properties when compared to those processed usi ng conventional treatments. This paper presents new possibilities of heat treatment for 42SiCr steel, which is a low-alloyed steel with a strength of 980 MPa and ductility of 30% in the basic state. Very high strength can be reached through conventional treatment, but ductility drops down to lower values. The aim of this experiment was to design and test an unconventional heat treatment procedure in order to reach a high strength of about 2000 MPa with ductility over 10%. For this purpose, the Q-P process was modified and optimized in several steps. The influence of the technological process para meters on the structure development was documented using metallography and the resulting mechanical properties were measured.