稀土元素Gd对2308双相不锈钢热变形行为的影响  

Effect of Gd on Thermal Deformation Behavior of 2308 Duplex Stainless Steel

作　　者：赵鹏飞 梁田[1] 陈波[1] 马颖澈[1] 刘奎[1] ZHAO Pengfei;LIANG Tian;CHEN Bo;MA Yingche;LIU Kui(Key Laboratory of Nuclear Materials and Safety Assessment,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院金属研究所核用材料与安全评价重点实验室,辽宁沈阳110016 [2]中国科学技术大学,安徽合肥230026

出　　处：《原子能科学技术》2022年第8期1671-1681,共11页Atomic Energy Science and Technology

摘　　要：为解决含Gd双相不锈钢热加工不足问题,本文以含2%Gd的双相不锈钢为研究对象,在不同温度下开展热模拟压缩实验,研究含Gd双相不锈钢热变形行为及组织演变。利用Gleeble-1500D热模拟试验机对含Gd双相不锈钢进行变形量为50%的单道次热变形试验。根据真应力-真应变曲线计算了该合金的热变形激活能Q_(d),建立本构方程。同时对热变形后的组织进行了分析,探究稀土元素Gd对含Gd双相不锈钢热变形行为的影响,结果表明,在热变形过程中,合金的动态软化机制主要为动态再结晶。合金包含两种含Gd析出相,即条带状的脆性析出相M_(3)Gd相和M_(17)Gd_(2)相(M=Fe、Cr、Ni),均为六方结构。当变形温度为1050℃时,脆性M_(3)Gd相破坏了基体的连续性,无法与基体协同变形,降低了合金的热塑性,导致合金在热变形过程中出现沿晶开裂。含Gd双相不锈钢适宜的热加工工艺区间的应变速率为0.01~0.1 s^(-1),变形温度为950~1000℃。In order to solve the problem of insufficient hot processing of Gd-containing duplex stainless steel,the 2%Gd duplex stainless steel was taken as the research object and carried out thermal simulation compression experiments at different temperatures to study the thermal deformation behavior and microstructure evolution of Gd-containing duplex stainless steel.The Gleeble-1500D thermal simulation testing machine was used to conduct a single-pass thermal deformation test with a deformation of 50%on the Gd-containing duplex stainless steel.According to the true stress-true strain curve,the thermal deformation activation energy Q_(d)of the alloy was calculated,and the constitutive equation was established.This equation can provide a theoretical basis for the selection of high temperature thermal deformation equipment and the prediction of high temperature deformation resistance.It also has a certain guiding significance for the control of material properties and the optimization of processing technology.At the same time,the microstructure after thermal deformation was analyzed to explore the effect of rare earth element Gd on the thermal deformation behavior of Gd-containing duplex stainless steel.The results show that the dynamic softening mechanism of the alloy is mainly dynamic recrystallization during hot deformation.Large-sized ferrite grains recrystallize to form fine equiaxed crystals,while part of the austenite grains grow along the rolling direction and become smaller in size.The alloy contains two precipitation phases Gd-containing,namely M_(3)Gd phase and M_(17)Gd_(2)phase(M=Fe,Cr,Ni),both of which have a hexagonal structure,and exist in the grain boundary or grains.TheM_(17)Gd_(2)phase has little effect on alloy workability.Compared with M_(17)Gd_(2),the M_(3)Gd phase on the grain boundary has a greater influence on the matrix.The brittle M_(3)Gd phase destroys the continuity of the matrix and cannot deform synergistically with the matrix structure.A large number of brittle M_(3)Gd phases reduce the therm

关 键 词：中子屏蔽材料 双相不锈钢 热变形 

分 类 号：TG33[金属学及工艺—金属压力加工]