Aminnudin, H. Suryanto, Suprayitno
Steel with very small grain has high strength but still have ductility. When the steel is heated to austenitic temperatures it can make the steel grains grow and reduce the hardness of the steel. To prevent this, it is necessary to know the effect of holding time on steel hardness. The hardness is indicating of grain growth of the steel. In this study, we examined the effect of holding time on hardness of very small grained steel. The heat treatment is carried out at 1100 degrees Celsius using an electric furnace. Micro hardness testing using the micro-Vickers method uses 300 grams of force and an indentation time of 10 minutes. Observation of microstructure is carried out with metallurgical microstructure. The etching solution for microstructure observation was nital solution. Heat treatment of steel powder mettallurgy with holding time of 60 minutes will cause a decrease in hardness from 261 to 207 and grain size growing from 3.2 μm to 6.3 μm. © 2020 Published under licence by IOP Publishing Ltd.
Department of Mechanical Engineering, Universitas Negeri Malang, Indonesia
