316L表面制备Ni-Al系金属间化合物层的耐铅铋腐蚀性能  

Lead-bismuth corrosion resistance of Ni-Al intermetallic compound layer prepared on 316L surface

作　　者：朱强[1] 姚书生 赵信毅 李洪亮 朱兆剑 Zhu Qiang;Yao Shusheng;Zhao Xinyi;Li Hongliang;Zhu Zhaojian(Jiangsu University,Zhenjiang 212013,Jiangsu,China)

机构地区：[1]江苏大学,江苏镇江212013

出　　处：《焊接》2022年第12期36-43,共8页Welding & Joining

摘　　要：利用激光熔覆技术在316L不锈钢表面熔覆一层Ni60合金粉末,采用热喷涂技术在Ni60合金涂层表面制备纯Al涂层,再通过620℃×5 h高温扩散试验,使Ni60合金涂层和纯Al涂层中间生成Ni-Al金属间化合物。最后把制备有Ni60合金和Ni-Al金属间化合物涂层试样置于液态铅铋合金中进行400℃×500 h腐蚀试验。采用SEM,XRD对金属间化合物涂层腐蚀前后的表面、截面的形貌、物相组成及元素分布进行测试,分析Ni60合金涂层和金属间化合物涂层在400℃液态铅铋合金中的腐蚀情况。试验结果表明,经过高温扩散试验,试样表面生成了一层由Ni_(3)Al,NiAl等组成的Ni-Al系金属间化合物;经过400℃液态铅铋合金腐蚀试验,Ni60合金涂层表面腐蚀较为严重,表面大量金属元素被氧化、溶解,在试样表面形成了不连续金属氧化物和腐蚀坑;Ni-Al金属间化合物涂层被氧化成为稳定的金属氧化物涂层,可以有效阻止Pb,Bi,O等元素渗透进入基体,提高316L的耐液态铅铋腐蚀性能。A layer coating of Ni60 alloy powder was deposited on the surface of 316L stainless steel by laser cladding technology,and pure Al coating was prepared on the surface of Ni60 alloy coating by thermal spraying technology.Then,Ni-Al intermetallic compound was generated between Ni60 alloy coating and pure Al coating by 620℃×5 h high temperature diffusion test.Finally,the specimens prepared with Ni60 alloy and Ni-Al intermetallic compound coating were placed in liquid lead-bismuth alloy for 400℃×500 h to conduct corrosion test.SEM and XRD were used to test morphology,phase composition and element distribution of surface and section of intermetallic compound coating before and after corrosion,and corrosion resistance of Ni60 alloy coating and intermetallic compound coating in liquid lead-bismuth at 400℃was analyzed.The test results showed that after high temperature diffusion test,a layer of Ni-Al intermetallic compound composed of Ni_(3)Al and NiAl was generated on the surface of specimens.After 400℃liquid lead-bismuth alloy corrosion test,surface corrosion of Ni60 alloy coating was more serious,a large number of metal elements on the surface were oxidized and dissolved,and discontinuous metal oxides and corrosion pits were formed on the surface of specimens.Ni-Al intermetallic compound coating was oxidized and became a stable metal oxide coating,which could effectively prevent Pb,Bi,O and other elements from penetrating into substrate and improve corrosion resistance of 316L to liquid lead-bismuth.

关 键 词：激光熔覆 高温扩散 金属间化合物 铅铋腐蚀 

分 类 号：TG456.7[金属学及工艺—焊接]