Effect of Heat Treatment on Grain Size and Mechanical Properties of 316 Austenitic Stainless Steel

Abstract

Grain growth is one of the three important stages take place during annealing of cold-worked materials after the process of recovery and recrystallization. This paper presents the experimental analysis of the grain growth kinetics and hardness of 316 austenitic stainless steel having grain size between 6µm and 69µm. The experiments were carried out for three different temperatures and represent microscope images of grain growth during isothermal annealing at (900oС, 1000°С and 1100oС) within 30, 60, 90 and 120 min respectively. The change of grain size as a function of annealing time for various temperatures have been presented in this study the value of the coefficient n for normal grain growth was determined and found to be in the range from 0.29 to 0.37. The investigation also included the determination of the activation energy for grain growth which found to be 104 KJ/mol. The hardness of 316 austenitic stainless steel has been measured at different grain sizes and the results indicated that the hardness decreased with increasing grain size and the data in general confirm the Hall-Petch equation.