Effects of Heat Treatment on Microstructure and Impact Resistance of High Manganese Steels

Abstract

High manganese steels are widely used as wear- and impact-resistant materials in many areas, especially in the mining, construction, cement, and metallurgy sectors, where it is extremely important to be able to work safely in high-stress conditions as well as resistance to abrasion under heavy loading conditions thanks to their unique work-hardening performance. At this point, the carbon and manganese ratio of the material has a considerable influence on the microstructure of the cast part after the heat treatment. Therefore, heat treatment conditions have to be determined appropriately depending on the chemical composition of the material. In this study, heat treatment processes were applied to high manganese steel specimens having GX120MnCr18-2 DIN standard at various austenitizing temperatures between 1030~1100 oC. The specimens were examined under an optical microscope and SEM/EDS analyses were performed. Impact resistance and hardness values of the above-mentioned specimens were measured via the tests performed with TS EN ISO 148-1 and TS EN 130 6508-1 standards, respectively. From these investigations, it was determined that the carbide solubility increased as the austenitizing temperature increased while the impact resistance first increased and then decreased.