The effect of austenitizing temperature on thenormalising processing behaviour of 34CrNiMo6 steel

Abstract

The aim of this study is to carry out research about the effect of austenitizing temperature of 34CrNiMo6 low alloy steel on the normalising heat treatment process. Moreover, a comparison of the austenite grain size that formed after the deformation at two austenitizing temperatures of 1100°C and 1200°C with that one resulted after the normalising process at temperature of 860°C. Moreover, to study the effects of increases of holding times of 6, 30 and 60 minutes at normalising process with both austenitizingon the grain size variation, and the consistency of microstructure, which in turn influences on the resulted mechanical properties. It was observed that deformation the specimens at austenitizing temperature of 1100 °C prior normalising process; gives a smaller grain sizes than those when using austenitizing temperature of 1200 °C. Furthermore, Increase in the normalising soaking times does have no influence the increasing of the grain size of austenite. However, it has an effect on The arrangement and shape of grains by making the grains equiaxed and creates a uniform structure. Furthermore, oxides scale thickness was observed at austenitizing temperature of 1200 °C, and particularly when soaking time at that temperature increased.