The study of diffusion annealing procedure on the chemical behaviour of mild steel

Abstract

Steel is often heat-treated under a controlled series of heating and cooling to achieve desired mechanical properties such as hardness, tensile strength and elongation depending on the application. However, structural damage can occur when mild steel is exposed to corrosive environments. In this study, diffusion annealing and quenching process were selected to analyse the microstructure and properties of mild steel and to determine the effect of corrosion on the properties of the mild steel. Mild steel samples were cut to dimensions of (75 x 25 x 3) mm, then heat-treated in an oven at 800 ° C, 900 ° C, and 1000 ° C for 2 hours of retention time, then quenched with oil, air-cooled. The heat-treated samples were subjected to a four-week corrosion test in sodium chloride solution to determine the effect of heat treatment on the microstructure and its corrosion resistance from the weight loss analysis. The characterisation of the sample was carried out using fluorescent X-rays, tensile tests, elongation and Rockwell hardness tests.