Austenite Stability in a 1500MPa Grade Cold-rolled Medium Manganese Steel
For the purpose of developing a 1500MPa grade steel sheet with excellent strength and ductility,a 10Mn1.5Al steel was employed to study austenite stability and microstructural evolution based on a novel processing of double annealing.After a conventional intercritical annealing to enrich austenite with manganese,the sample were heated to a much higher temperature for a very short time to generate lean manganese austenite and enriched manganese austenite,thus the microstructure of martensite plus austenite can be obtained when heated at a temperature higher than Ac3.The experimental results showed that with increasing annealing temperature,the tensile strength and yield strength went up.When the annealing temperature was higher than 820℃,the microstructure consisted of martensite plus austenite and the tensile strength almost remained invariant with annealing temperature.The tensile strength and elongation of 1537MPa and 25.1% were achieved for the 820℃ condition.The volume fractions of austenite and martensite were identified by means of X-ray diffraction (XRD).It was found that with increasing annealing temperature the retained austenite volume fraction decreased,and the ductility also have a gradual downtrend.The related austenite stability was discussed in this paper as well.
medium Mn steel cold-rolled austenite martensite
ZHANG Yulong HAN Qihang Wang Li
Research Institute, Baosteel Iron & Steel Co. Ltd., Shanghai 201900, China;State Key Laboratory of Development and Application Technology of Automotive Steels(Baosteel), Shanghai 201900, China
国际会议
成都
英文
45-48
2016-11-16（万方平台首次上网日期，不代表论文的发表时间）