Evaluation on microstructure and hardness of heat treated AISI 1050

Due to its chemical composition, carbon steel has limited physical and mechanical properties. This study aims to analyze the effect of the cooling rate given during the heat treatment process on changes in the microstructure and hardness of carbon steel AISI 1050. The heat treatment was carried out at 800oC with 1 hour holding time. In annealing, air inside the furnace used as cooling media so that the cooling rate is very slow. While quenching used water as a cooling medium so that the cooling rate is very fast. From the results of the ASTM E340-95 metallographic test, it was found that there was a change in the microstructure of the steel from the heat treatment of quenching (CSQ) and annealing (CSA) when compared to steel without treatment (CSTP). Rockwell hardness testing according to ASTM E18-15 standards shows the hardness slightly decreased to 41.83 HRC at CSA, while CSQ has the highest hardness due to the phase presents