Material Science and Metallurgy

9

Heat Treatment of Steels

9.1 INTRODUCTION

Heat treatment of steels is as important as its production for the development of desired mechanical, electrical and chemical properties, and the commercial alloys are invariably heat treated. Steel is heated to a specified temperature and then cooled at a controlled rate for the improvement of mechanical properties of the steel such has hardness, strength and ductility of the material. The heat treatment processes are carried out for specific industrial purposes: (a) to relieve internal stresses in the steel, which have crept in the steel due to mechanical deformation, (b) to improve machinability for easy machining of the steel products, (c) to improve tensile strength and tensile Young’s modulus, ...