固溶处理对Fe-Cr-Ni-Al合金组织转变及元素扩散的影响  

Effect of solution treatment on microstructure transformation and element diffusion of Fe-Cr-Ni-Al alloy

作　　者：周起云 石增敏 谢镐 戴雷 Zhou Qiyun;Shi Zengmin;Xie Hao;Dai Lei(School of Materials and Chemical Engineering,Three Gorges University,Yichang Hubei 443002,China;Hubei Key Laboratory for Design and Maintenance of Hydropower Machinery and Equipment,Three Gorges University,Yichang Hubei 443002,China)

机构地区：[1]三峡大学材料与化工学院,湖北宜昌443002 [2]三峡大学水电机械设备设计与维护湖北省重点实验室,湖北宜昌443002

出　　处：《金属热处理》2022年第5期98-104,共7页Heat Treatment of Metals

基　　金：国家重点研发计划(2020YFB2010301)。

摘　　要：利用OM、SEM等方法研究Fe-Cr-Ni-Al合金在固溶处理过程中元素的扩散以及相转变,同时针对不同降温速率的DSC数据建立了有关γ相转变的JMAK模型。结果表明,吸铸成形Fe-Cr-Ni-Al合金的室温组织基体为γ相+δ铁素体相;经过1150℃固溶处理,合金中γ相含量增高,δ铁素体相含量下降。在升温阶段发生了δ→γ的相转变,而在保温阶段发生了γ→δ的相转变;通过固溶处理,δ铁素体相、γ相分别演变成更为明显的富Cr相和富Ni相,不同分布位置的σ相之间Cr和Ni元素差异增大,与其所在的基体的成分偏析逐渐变小;通过奥氏体相转变的JMAK模型可知,冷却速度增大时,γ相转变的起始温度变低,同时转变的温度区间增大,反应所引起的能量变化也增大。Diffusion of elements and phase transformation of the Fe-Cr-Ni-Al alloy during solution treatment process were studied by means of OM, SEM and other methods, and a JMAK model of γ phase transformation was established by DSC data at different cooling rates. The results show that the matrix phase at room temperature of the as-cast Fe-Cr-Ni-Al alloy is γ phase and δ phase. After solution treatment at 1150 ℃, the content of the γ phase in the alloy increases, and the content of the δ phase decreases. The phase change of δ→γ occurs in the heating stage, and the phase change of γ→δ occurs in the isothermal soaking stage. Through the solution treatment, δ phase and γ phase evolve into a more obvious Cr-rich phase and Ni-rich phase, the difference of Cr and Ni elements between σ phases which located in different positions increases, and the component segregation between σ phases and their matrix decreases gradually. It can be proved by the JMAK model of austenite phase transition that the greater the cooling rate, the lower the starting temperature of the γ phase transition, and the larger the temperature interval of the transition, the greater the energy change caused by the reaction.

关 键 词：Fe-Cr-Ni-Al合金 固溶处理 元素扩散 相转变 JMAK模型 

分 类 号：TG161[金属学及工艺—热处理]