一种含氮Cr-Ni型奥氏体不锈钢的工艺设计与热处理研究  

Process Design and Heat Treatment Research of A Nitrogen-containing Cr-Ni Type Austenitic Stainless Steel

作　　者：张玉碧[1] 刘海定[2] 王东哲[2] 赵永涛[1] 

机构地区：[1]河南工程学院机械工程学院,河南郑州451191 [2]重庆材料研究院有限公司,重庆400707

出　　处：《热加工工艺》2016年第18期177-181,187,共6页Hot Working Technology

基　　金："863"国家高技术研究发展计划项目(2013AA031005);河南工程学院博士基金项目(D2015015)

摘　　要：含氮奥氏体不锈钢是资源节约型不锈钢的典型代表。本文依据含H2S油气环境对不锈钢耐蚀及力学性能的要求,对一种Cr-Ni型奥氏体不锈钢的成分、冶金工艺进行了设计,并对该不锈钢的铸态、锻态、固溶态组织及力学性能进行了研究。结果表明：该不锈钢铸态为单一奥氏体的枝晶组织,沿晶界析出大量富Cr Mo的滓相;经1150℃锻造后,钢中滓相消失,获得细化的孪晶组织,并具有优良的综合力学性能。经900～1000℃固溶处理,沿晶界有大量Cr N、Cr N2氮化物析出,并随升温沿垂直于锻造方向呈带状偏聚;在1050～1100℃沿孪晶组织发生再结晶,基体中晶粒长大,强度下降,塑韧性增加。Nitrogen-containing austenitic stainless steel is a typical representative of the resource-saving stainless steels. According to the requirements of corrosion resistance and mechanical properties of the stainless steels in H2S containing oil and gas environment, the composition and metallurgical process of a Cr-Ni type austenitic stainless steel were designed. And the microstructure and mechanic properties of the stainless steel in as-cast, forged and solution-aging states were studied. The results show that the stainless steel is the single austenite dendritic microstructure, and a large number of CrMo-rich σ phase is precipitated along the crystalline boundary. After forging at 1150℃, σ phase in the steel disappears, and the fine twin-grain microstructure, which has excellent comprehensive mechanical properties, is obtained. After solution treatment at 900-1000℃, a number of granular CrN, CrN2 nitrides are precipitated along the grain boundaries, which are zonal segregation along the vertical direction of the forging with the rising temperature. At 1050-1100℃, recrystallization occurres along the twin microstructure, the grains in the matrix grow up, the strength decreases, and plasticity and toughness increase.

关 键 词：含氮奥氏体不锈钢 工艺设计 固溶热处理 

分 类 号：TG142.24[一般工业技术—材料科学与工程]