Pengaruh Proses Hardening Konvensional Terhadap Kekerasan Material Baja AISI L6

This study investigates the influence of austenitizing temperature and quenching media on the hardness of AISI L6 tool steel during conventional hardening, and identifies the optimal heat treatment parameters for the fabrication of a chopper-type machete. Hardening was performed at three austenitizing temperatures 800°C, 850°C, and 900°C using two quenching media: brine solution and oil. Rockwell C hardness testing was conducted on AISI L6 specimens with an initial hardness of 17.1 HRC. Results revealed that higher austenitizing temperatures generally increased hardness. The maximum hardness improvement, 66%, was achieved at 900 °C with brine quenching, producing a hardness of 51.2 HRC. Oil quenching at the same temperature resulted in a 56% improvement, reaching 39.6 HRC. The superior hardness obtained with brine was attributed to its higher cooling rate, which promotes rapid martensitic transformation. Considering both hardness and dimensional stability, an austenitizing temperature of 850°C combined with brine quenching is recommended as the optimal heat treatment, delivering a hardness of 47.7 HRC with adequate toughness for impact resistance.