Effect of heat treatment on mechanical and microstructure properties from 0.21C-0.44Mn-0.65Cr-1.2Ni lateritic steel

Nowadays, along with the era that moves forward, the utilization of steel is developing rapidly in the infrastructure industry. It has been researched about laterite steel, which becomes alternative steel materials. Because of the laterite steel is the alternative material, the heat treatment process has been chosen to know about mechanical properties and microstructures that can be formed in the laterite steel. In this research, laterite steel, who has 0.21%C, 0.44%Mn, 0.65%Cr, and 1.2%Ni as the main composition, be heated on austenite temperatures that are 800oC for 30 minutes. After that, the quenching process is carried out in water and oil as the cooling medium required. And the final process is tempering process to complete this study with the tempering temperature 100 and 200oC for 45 minutes. The result shows that heat treatment process increased mechanical properties for laterite steel with the value of the tensile strength, hardness, and impact toughness are 14.88 N/mm2 for UTS and 10.27 N/mm2 for YS; 830 HV; and 0.047 J/mm2. Similarly, the microstructures formed is dominated by 62.74% of martensite structure.