MICROSTRUCTURE EVOLUTION AND MECHANICAL PROPERTIES OF HOT-ROLLED MEDIUM MANGANESE TRIP STEELS

摘要

Mechanical properties of TRIP steels have much to do with the amount and stability of retained austenite. In the present work, two hot-rolled TRIP steels with different manganese contents(8 and 11 mass percent)possess a large volume fraction of austenite by solution-treated in the range of 750-800°C for lh, resulting in a good combination of total elongation of 30-40% and ultimate tensile strength of 800-1100 MPa and this was found to have a similar or higher level of tensile properties compared with other TRIP steels. In the meantime, less cold-rolling work or annealing time was required in the present work. It was found that the mechanical properties of the experimental steels were mainly attributed to the enhanced TRIP effect due to the large fraction of austenite which was influenced by the manganese content and heat treatment.