Cr涂层对Zr-4合金蠕变行为的影响  

Effect of Cr coating on creep behavior of zircaloy-4 alloy

作　　者：左鼎 杜沛南 罗威 陈寰 王昱 韦天国[2] 张瑞谦[2] 刘会群[1,3] Ding ZUO;Pei-nan DU;Wei LUO;Huan CHEN;Yu WANG;Tian-guo WEI;Rui-qian ZHANG;Hui-qun LIU(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China,Chengdu 610213,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中国核动力研究设计院反应堆燃料及材料重点实验室,成都610213 [3]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第5期1533-1546,共14页中国有色金属学报（英文版）

基　　金：Key Project of uclear Safety and Advanced Nuclear Technology,China(No.2019YFB1901002);Project supported by the State Key Laboratory of Powder Metallurgy,Central South University,China。

摘　　要：报道化学气相沉积Cr涂层对Zr-4合金蠕变性能的影响以及Cr涂层在服役温度下的热稳定性。利用扫描电镜、电子探针显微分析和电子背散射衍射研究样品的显微组织。结果表明:样品Zr-4基体中晶粒呈等轴状,存在明显的<0001>//ND织构。蠕变后涂层样品的Zr-4合金基体中亚晶界数量明显低于无涂层样品Zr-4合金基体中亚晶界数量,表明Cr涂层显著降低了Zr-4合金基体在蠕变过程中承载的应力,提高了合金的抗蠕变性能。Cr涂层在长时间扩散实验中保持高稳定性。涂层在高蠕变应力下(350℃时不小于157 MPa,400℃时不小于137 MPa)出现裂纹。系统总结蠕变断裂的数据,得到了关于稳态蠕变速率与蠕变断裂时间的Monkman-Grant关系式。The effects of Cr coating,deposited by chemical vapor deposition,on the creep properties of Zr-4 alloy and the results for its stability during long-time service were reported.Its microstructure was studied by scanning electron microscopy,electron probe microanalysis,and electron backscatter diffraction.Results show that the grains of the Zr-4 matrix were equiaxed,exhibitingá0001ñtexture parallel to the normal direction(á0001ñ//ND).Moreover,after the creep test,coated samples displayed a lower number of subgrain boundaries within their matrix compared with uncoated samples.Thus,the application of a Cr coating is instrumental in minimizing the stress on Zr-4,ultimately contributing to an enhancement in creep resistance of the coated samples.The Cr coating exhibits a high stability during long-term diffusion test.The coating cracks at a minimum stress of 157 MPa at 350°C and 137 MPa at 400°C.The Monkman-Grant relationship between the steady-state creep rate and creep fracture time was derived using a systematic summary of data pertaining to creep fracture.

关 键 词：ZR-4合金 Cr涂层 蠕变行为 显微组织 热稳定性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]