PENGARUH VARIASI TEMPERATUR HOLDING TIME TERHADAP KEKERASAN DAN BEBAN IMPAK BAJA AISI 1045 DENGAN MEDIA PENDINGIN OIL

Hardening is one method to increase the hardness of a material with the aim of making the material resistant to friction and not easily broken. The hardening process will be optimal if the temperature and cooling media used are considered. This research is experimental using AISI 1045 steel specimens with a length of 55 mm, a width of 10 mm, and a thickness of 10 mm. The number of specimens tested was 10 specimens. The specimens were given heat treatment (hardening) with temperature variations of 800°C, 850°C, and 900°C with a holding time of 30 minutes, followed by rapid cooling using oil media. After that, the hardness of the specimen was measured using the Rockwell Cone Hardness (HRC) test and the Charpy impact test. The results showed that at a temperature of 800°C, the average hardness value was 56 HRC, and the energy absorbed was 21,890 J. At a temperature of 850°C, the average hardness value decreased to 51.6 HRC with an absorbed energy of 30,894 J, while at a temperature of 900°C, the average hardness value becomes 45.6 HRC with an absorption energy of 32,719 J. In conclusion, there is a significant effect of the variation in hardening temperature on the hardness and impact value of AISI 1045 steel with oil cooling media. Increasing temperature correlates with a decrease in hardness value and, conversely, correlates with an increase in absorption energy and impact value of AISI 1045 steel