Pengaruh Temperatur Tempering Terhadap Kekerasan Dan Struktur Mikro Baja Aisi 1045 Yang Diquenching Dalam Media Pendingin Tersirkulasi

Abstract

Steel AISI 1045 is steel classified as medium carbon steel because it has a carbon content of 0.45%.The characteristics of steel itself are sometimes not in accordance with the needs required,therefore the steel requires other treatments to change the properties and structure of steel AISI1045. The characteristics of steel can be changed by giving heat treatment, one of the processescarried out is the quenching tempering process. Quenching is a metal working process with rapidcooling to a predetermined variety of media with the aim of increasing the hardness of AISI 1045steel, while tempering is the process of reheating hardened steel with the aim of obtaining hightenacity and toughness.The quenching process uses a temperature of 800 °C with a waiting time of60 minutes and then cooled quickly with variations of diesel, water, and salt water with a 180°circulating process. While the tempering temperature variations used are 450 °C, 550 °C, and 650°C with a waiting time of 60 minutes. The results of the hardness test using the Rockwell method. inraw material testing get a value of 61.33 HRB hardness. The quenching results circulated in thesolar media are (80.6 HRB, 79.3 HRB, 81.3 HRB), the value of violence in the water media (89.3HRB, 89 HRB, 89.6 HRB), and salt water media (94,6 HRB, 96 HRB, 94.6 HRB). The hardnessvalue of temperature temperament 450 °C solar media (72.6 HRB 73 HRB, 72.6 HRB), water media(83.6 HRB, 82.6 HRB, 83 HRB), salt water (86.3 HRB, 86.6 HRB, 87.3 HRB). Temper temperaturehardness value of 550 ° C solar media namely (70.3 HRB, 70.3 HRB, 70.6 HRB) water media (81.3HRB, 81.3 HRB, 80.6 HRB) salt water media (84,3 HRB, 83.6 HRB, 84.6 HRB). The hardness valueof temperature variation of 650 °C, solar media are (68.3 HRB, 68.6 HRB, 68.6 HRB) water media(79 HRB, 79.3 HRB, 79.3 HRB) and salt water media (81,3 HRB, 81.6 HRB, 82 HRB). Themicrostructure obtained in quenching is the martensite structure and the tempering structure istemper martensite.Keywords: AISI 1045, quenching, tempering, martensite, ferrite, pearlite, HRB