摘要
利用盐浴热处理、扫描电镜、X衍射、拉伸试验等实验手段,辅以相图计算及显微组织预测技术,对一种含1.5%Al的冷轧相变诱导塑性(TRIP)钢在370℃到450℃贝氏体区等温后得到的组织与性能进行了研究,探讨贝氏体区等温工艺对相变行为、显微组织及力学性能的影响。结果表明:藉热处理工艺优化等措施,采用Al完全替代Si设计生产高性能冷轧TRIP钢是可行的。贝氏体区等温相变过程中Al元素有效抑制奥氏体中碳化物的析出,获得了数量多稳定性强的残余奥氏体;其中400℃等温180s的工艺使试验钢强度为756MPa时其伸长率达34.2%,但试验钢在450℃等温180s后将产生一定数量的对强塑积不利的马氏体。
Microstructure and mechanical properties of the 1.5Al %-alloyed cold rolled TRIP steel annealed at three isothermal bainite temperature （IBT, 370-450℃ ） were researched by means of SEM, X-ray, tensile test and prediction calculation on fraction of phases. The evolution of austenite during IBT and the effect of microstructure on mechanical properties were investigated. The results show that the substitution of Si by Al to produce a high performance TRIP steel is feasible by optimizing the process of heat treatment. Addition of aluminium in the alloys inhibits cementite formation during bainite transformation region. So a significant amount austenite is retained in steel at room temperature. The stability of retained austenite obtained by isothermal bainite treatment at 400℃ is higher than that at other temperatures, and instantaneous strain hardening exponent （nincr） maintains to a higher value during further straining, which results in a larger elongation. The tensile strength of the steel treated at 400℃ for 180s is 756MPa, elongation is 34.2% . Some martensite is probably formed after treating at 450℃ for 180s, which is detrimental to properties.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2009年第5期68-73,共6页
Transactions of Materials and Heat Treatment
基金
国家"十一五"配套研制项目:JPPT-115-2-712
关键词
相变诱导塑性钢
铝
贝氏体等温退火
残余奥氏体
力学性能
TRIP steel
Al
isothermal bainitic transformation（IBT）
retaineu austenite
mechanical properties
