KARAKTERISASI KEKERASAN DAN STRUKTUR MIKRO BAJA AISI 410 PADA PROSES TEMPERING DENGAN VARIASI MEDIA PENDINGIN
Heat treatment is a process carried out with the aim of changing the characteristics of metals and alloys with how to change the microstructure through the heating process and cooling speed regulation with or without change the chemical composition of these metals and alloys. In AISI 410 steel, the characteristic changes observed in this study were the value of hardness, and microstructure shape. Material samples heated to a temperature of 9000C and held for 45 minutes, a variety of cooling medium used are water, used oil, and SAE 20W-50 oil. In the process, tempering the material sample returns heated to a temperature of 3000C and held for 15 minutes, then cooled in the room open. The results showed that the sample quenching water had the highest hardness, namely 378 HV. Followed by quenching of SAE 20W-50 oil and used oil with grades of 377 and 362 HV, respectively. The increase in hardness value occurs due to changes in the micro structure that occur due to the heat treatment process. Microstructure formed in AISI 410 steel after heat treatment is martensite lath, ferrite and austenite.