Abstract
The present paper is concerned with the nature of the martensite, which provides the basis for the maraging treatment. Rather than forming martensite during cooling, 1RK91 develops martensite when held at a constant temperature in a range from room temperature and below. Isothermal martensite formation showing C-curve kinetics was found to occur in the maraging steel 1RK91, the nose temperature being about {minus}40 C. The kinetics was found to be enhanced for higher austenitizing treatment temperatures, presumably through a combination of larger grain size and a larger number of quenched in nuclei for isothermal martensite transformation. Experiments involving different cooling rates showed that fast cooling enhanced the transformation kinetics. Based on this observation it is suggested that quenched-in vacancy clusters provide suitable strain embryos for isothermal martensite nucleation.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
