Cryogenic heat treatment of the ferrous materials – a review of the current state

¹ Department of Mechanical Engineering, Tiran Branch, Islamic Azad University, Isfahan, Iran
e-mail: k_amini@iautiran.ac.ir
² Department of Materials Science and Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran
³ Department of Materials Science and Engineering, Shiraz university, Shiraz, Iran

Received: 1 July 2016
Accepted: 8 August 2016

Abstract

Deep cryogenic treatment is a supplementary heat treatment which has been used industrially since the 70s in the last century. This process includes lowering the samples temperature down to that of the liquid nitrogen (–195 ^◦C), holding the samples at that temperature for some periods of time and then warming the samples gradually up to room temperature. This process is regularly used for different kinds of steels, including the HSS, tool steels, cast iron and carburized steels. This study attempts to clarify the effect of different environmental variables on the materials, subjected to the deep cryogenic heat treatment, as well as explaining the common theories about the cryogenic behavior of the ferrous materials.