Effect of annealing temperature and time on microstructure and tensile properties of a cold-rolled multi-phase medium Mn steel

• Main Authors: Chih-yu Chan, 詹智宇
• Other Authors: Chih-Pu Chang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/75762242644863437382

碩士 === 國立中山大學 === 材料與光電科學學系研究所 === 104 === This study explores the effect of cold rolling and intercritical annealing on the microstructure and tensile properties of a medium manganese steel. The effects of annealing time and temperature of intercritical annealing have been studied. It was found that cold rolling followed by 750oC annealing for 10 minutes gave the best tensile properties. 25% and 50% cold roll reduction gave similar tensile properties. When the annealing temperature was increased from 700 to 750oC, more equiaxed grains were formed, and the alloy distribution was homogenized. When the annealing time was increased to 10 hours at 750oC, a lot of athermal martensites were formed. Increasing annealing temperature can give higher fraction of austenite, but the manganese content of austenite grains was decreased, so that caused the decrease of austenite stability.