热处理工艺与合金成分对国产新锆合金拉伸性能及显微组织的影响  

Effect of Heat Treatment on Tensile Properties and Microstructure of New Domestic Zirconium Alloys

作　　者：陈乐[1] 杨忠波[1] 邱军[1] 梁波[1] 李卫军[1] 洪晓峰[1] 王练 

机构地区：[1]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 [2]国核宝钛锆业股份有限公司,陕西宝鸡721000

出　　处：《核动力工程》2017年第6期129-133,共5页Nuclear Power Engineering

基　　金：大型先进压水堆核电站重大专项(2011ZX06004-023)

摘　　要：采用MTS材料试验机研究了去应力态和再结晶态的SZA4(Zr-0.8Sn-0.25Nb-0.35Fe-0.1Cr-0.05Ge)、SZA6(Zr-0.5Sn-0.5Nb-0.3Fe-0.015Si)2种不同成分的锆合金在室温和385℃的拉伸性能,采用扫描电镜(SEM)分析了断口形貌,采用透射电镜(TEM)分析合金与第二相的微观结构。结果表明:各材料均有较好的力学性能,SZA4-450℃的强度最高,SZA4-560℃和SZA6-560℃的塑性最好;各材料的微观断口形貌均为韧窝,表明断裂方式为韧性断裂,同时可见大量的第二相粒子均匀、弥散地分布在基体中;SZA-4中存在2种密排六方结构(HCP)的第二相,尺寸较小的为Zr(Nb F20e Cr)2,尺寸较大的为Zr(Nb Fe Cr Ge)2,SZA-6中存在面心立方结构(FCC)的(Zr Nb)2 Fe和HCP结构的Zr(Nb Fe)2 2种第二相。最后分析了热处理工艺和合金成分对拉伸性能及显微组织的影响,认为热处理工艺的影响起主要作用。The tensile properties of stress relieved （SR） and recrystallized （RX） alloys, with two different compositions, namely SZA4（Zr-0.8Sn-0.25Nb-0.35Fe-0.1Cr-0.05Ge） and SZA6（Zr-0.5Sn-0.5Nb-0.3Fe-0.015Si） at room temperature （RT） and 385℃ were studied by MTS material test machine, the fracture morphology of alloys was observed by scanning electron microscopy （SEM） and the microstructure was observed by transmission electronic microscopy （TEM）. The results showed that each alloy was excellent on mechanical properties, SZA4-450 was the strongest while SZA4-560℃ and SZA6-560℃had the best elongation.The fracture mode of alloys was ductile, according with lots of dimples in the fracture morphology, second phase particles （SPPs） which were also observed by SEM, distributing in the base uniformly and dispersely. There were two kinds of SPPs which were observed by TEM in SZA-4 alloy, one was Zr（NbFeCr）2 with a smaller size and the other was Zr（NbFeCrGe）2 with a larger size, both of them had a HCP structure. In SZA-6, （ZrNbhFe SPPs with a FCC structure and Zr（NbFe）2 SPPs with a HCP structure was found. The effect of heat treatment and composition on alloys was analyzed, showing that the heat treatment played a dominant role.

关 键 词：锆合金 拉伸性能 第二相 韧窝 

分 类 号：TU502[建筑科学—建筑技术科学]