Pengaruh Waktu Proses Austemper Pada Paduan Fe-Cr-20MnTerhadap Struktur Mikro Dan Sifat Mekanik

Abstract

Fe-Cr-20Mn alloy steel is a material that is widely used in industry because it has a combination of strength and good corrosion resistance. One of the heat treatment methods that can improve the mechanical properties of this material is the austempering process. This study aims to analyze the effect of austempering process time variation on the microstructure and mechanical properties of Fe-Cr-20Mn steel. The specimens were heated at 900°C for 1 hour for the austenitization process, then dipped in molten salt at 400°C with a variation of holding times of 10, 20, and 30 minutes before being cooled in water. Tests carried out include chemical composition test, microstructure test, Vickers hardness test, tensile test, and Charpy impact test. The test results show that the longer the austemper time, the larger the austenite grains and the smaller the ferrite structure. The highest hardness was obtained at an austemper time of 10 minutes at 377.5 HV, while the tensile strength decreased from 657.3 MPa to 512.5 MPa as the austemper time increased. The toughness of the material also decreased, from 109 J/mm² at 10 minutes to 104 J/mm² at 30 minutes.