Author : Daniel Martin Sandhi, Rahul Davis, Ashish Masih, Roshni Deepika Hemrom, Ashish Samual and Noel Vinsent Chand

Thermal treatments have been widely used as a medium of improving the physical and mechanical properties of tool steels. A Comparative study on conventionally heat treated and cryogenic treated S7and M1 specimens has been presented in this paper. Now a day’s cryogenic treatment is regarded as one of the most important processes in the field of manufacturing, it is a contemporary method of processing metals to make them more wear resistant and durable. Cryogenic treatment is an appended process to conventional heat treatment process. The main objective of cryo-treatment is to convert retained austenite to martensite. Due to this conversion, all the properties of the metal increase. Here specimens are initially subjected to conventional heat treatment at austenitizing temperature of the metals respectively and are subjected to Shallow Cryogenic Treatment at -84oC for 3 to 8 hours or Deep Cryogenic Treatment(DCT) at -196oC for 24 hours. The changes in the microstructure were studied using radical metallurgical microscope. Here investigation is to compare about the microstructure, and durability of the specimens before and after cryogenic treatments.

Keywords: Tool steel, Heat treatment, Cryogenic treatment, Retained Austenite, Martensite, Microstructure

Article published in International Journal of Current  Engineering  and Technology, Vol.4,No.3 (June- 2014)