INFLUENCE OF HEAT TREATMENT ON MECHANICAL PROPERTIES OF MILD STEEL

Abstract

. In manufacturing and metallurgical industries, the metal is heated above the critical temperature in which micro-structural transformation has been take place, to change the desirable microstructure and mechanical properties such as tensile strength, hardness, toughness, fatigue strength etc. The physical properties have been obtain through heat treatment mainly depends upon the heating temperature, rate of heating and the cooling medium. Some of the widely used cooling mediums are air, water, salt bath, oil, etc. Mild steel is categories as low carbon steel with a low percentage of carbon by weight. The amount of carbon present in mild steel is about 0.05% to 0.25% by weight. The presence of less carbon the mild steel is normally more ductile, machinable, malleable, corrosion resistance and weldability as compared to high carbon steel. Due to these characteristics it has been more its application in various metallurgical, mechanical and manufacturing industries. Moreover heat treatment has been carried out to enhance the mechanical properties such as hardness, tensile strength, toughness etc.

In this study, the mild steel specimens are to be heat treated at certain temperatures above the austenite and quenched in the certain medium and to observe the changes in mechanical properties. Result shows that the mechanical properties of mild steel samples are improved by different treatment processes with different medium of cooling.

Keywords: Mild steel, heat treatment, hardness, tensile strength, toughness, micro-structure, universal testing machine,