高强度TRIP钢中残留奥氏体稳定性  

Stability of retained austenite in a high strength TRIP steel

作　　者：吴其浩[1] 熊杰[1] 朱娜琼[1] 何燕霖[1] 李麟[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《材料热处理学报》2013年第11期89-92,共4页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金项目(50971137;50934011)

摘　　要：采用室温拉伸实验并结合SEM、TEM、XRD以及X射线应力仪原位测定技术,研究不同TRIP处理条件下的高强度TRIP钢的力学性能与显微组织。结果表明,当两相区处理为800℃×3 min,贝氏体区处理为400℃×5 min时,试验钢的抗拉强度可达975.68 MPa,伸长率为27.88%,强塑积可达27202 MPa%;在外加应力作用下,TRIP钢中残留奥氏体在屈服点之后发生向马氏体的转变,残留奥氏体向马氏体的转变为应变诱发相变;同时,残留奥氏体随应变增大而降低的趋势减缓,其强塑性越好,残留奥氏体发生向马氏体的渐进式转变使其TRIP效应更为显著;此外,试验钢中残留奥氏体多呈薄膜状,具有较好的强塑性。Mechanical properties and microstructure of a high strength TRIP steel with different heat treatments were investigated by tensile test, SEM, TEM, XRD and X-ray in situ measurement. The results show that the best mechanical properties are obtained when the steel is heat-treated at 800 ℃ for 3 min in two-phase region and then at 400 ℃ for 5 min in bainite region, the ultimate tensile strength is 975.68 MPa, the elongation is 27.88%, and the product of strength and ductility is 27202 MPa%, respectively. The phase transformation from retained austenitc to martensite occurs after yielding point due to strain induced transformation under the external force. The tendency of the retained austenite transformation decreases as the strain increases, indicating a progressive transformation from retained austenite to martensite by TRIP effect. The steel with stable film retained austenite shows better product of strength and plasticity.

关 键 词：相变诱发塑性(TRIP)钢 原位测量 残留奥氏体 贝氏体区等温 渐进式转变 

分 类 号：TG135.1[一般工业技术—材料科学与工程]