THE INFLUENCE OF HEAT TREATMENTS ON MICROSTRUCTURE AND HARDNESS OF MANGANESE STEEL ASTM A128 GRADE C

• Main Author: Ariella Gumelar, Evan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68869
• Institution: Institut Teknologi Bandung

The rapid development of heavy industry has caused serious problems which are most related to mechanical failure as abrasive wear mode. Hence, the need for materials with high toughness and work-hardening capacity becomes more important. Austenitic manganese steel or Hadfield steel is widely used because of its high impact toughness and work-hardening capacity but the use of this steel has a problem, since the intergranular carbide can bring the brittleness problem caused by the solidification process. The onestep and two-step heat treatment processes along with rapid quenching are applied to solve this problem. This research aims to learn the differences between heat treatment results in microstructure and its hardness. This research used 1000? for two hours, a two-step heat treatment with 595? (ten hours of holding) followed by 980? (two hours of holding), also another two-step heat treatment with 700? (three hours of holding) and followed by 1000? (one-half hours of holding). All three methods are followed by rapid quenching. Hardness test and microstructure observation then need to be done to see any differences. All three methods succeeded to dissolve intergranular carbide. Also, the two-step process succeeded to create dispersion-hardened austenite and proved to have higher hardness than single-phase austenite. The heat treatment with 700? (three hours of holding) followed by 1000? (one-half hours of holding) results in the lowest hardness compared to other methods. Fine carbide with higher size results in lower hardness.