H62黄铜/TC4钛合金焊接件腐蚀行为研究  

Corrosion Behavior of H62 Brass Alloy/TC4 Titanium Alloy Welded Specimens

作　　者：白苗苗 白子恒 蒋立 张东玖[3] 姚琼 魏丹[4] 董超芳[1,2] 肖葵 BAI Miaomiao;BAI Ziheng;JIANG Li;ZHANG Dongjiu;YAO Qiong;WEI Dan;DONG Chaofang;XIAO Kui(Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;Corrosion and Protection Center,University of Science and Technology Beijing,Beijing 100083,China;China Xichang Satellite Launch Center Key Laboratory of Reliability Technology for Space Launch Site,Haikou 571000,China;Service Center for China Science and Technology Association,Beijing 100081,China)

机构地区：[1]北京科技大学新材料技术研究院,北京100083 [2]北京科技大学腐蚀与防护中心,北京100083 [3]西昌卫星发射中心航天发射场可靠性技术重点实验室,海口571000 [4]中国科学技术协会服务中心,北京100081

出　　处：《中国腐蚀与防护学报》2020年第2期159-166,共8页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(51671027);国家重点研发计划(2017YFB0304602);国家材料环境腐蚀平台(NECP)。

摘　　要：采用真空扩散焊接进行H62黄铜与TC4钛合金的焊接,并使用3.5%(质量分数)NaCl溶液对焊接件进行全浸实验。利用SEM及EDS对焊缝两侧的微观形貌及元素分布进行分析,并分析距离焊缝不同距离的区域内,H62黄铜的微观腐蚀形貌的差异;利用扫描Kelvin探针测试焊缝区及其两侧基底合金的表面电位随浸泡时间的变化,分析焊接件的电偶腐蚀规律;利用XPS分析焊接后的H62黄铜与TC4钛合金区域的化学成分,并分析其腐蚀机理。结果表明,由真空扩散焊连接的H62黄铜及TC4钛合金焊缝间距约为25~30μm;浸泡实验初期H62黄铜电位略高于TC4钛合金的,但是随着浸泡实验时间延长,H62黄铜的表面电位开始逐渐下降,后期(4 h)表面电位开始低于钛合金的;同时,距离TC4钛合金较近区域的H62黄铜腐蚀较焊缝远处的更严重;H62黄铜浸泡实验后的腐蚀产物主要包括CuO,Cu2O,CuCl,CuCl2和Cu(OH)2,而TC4钛合金表面主要为含有TiO2和Ti2O3的氧化膜。说明浸泡在3.5%NaCl溶液中的H62黄铜/TC4钛合金焊接试样存在电偶腐蚀倾向,H62黄铜作为阳极被加速腐蚀,TC4钛合金作为阴极被保护,阴极和阳极区域间的电偶对距离作用越长,腐蚀程度越轻。The corrosion behavior of vacuum diffusion welded component of H62 brass and TC4 Tialloy in 3.5%(mass fraction)NaCl solution for up to 24 h was investigated by means of immersion test,scanning Kelvin probe test,scanning electron microscopy attached with EDS and X-ray photoelectron spectroscopy.The results demonstrate that the weld seam width of the jointed H62 brass and TC4 Ti-alloy is about 25~30μm,and the free corrosion potential of H62 brass is slightly higher than that of TC4 Ti-alloy at the initial stage of immersion test.However,with the prolongation of immersion time,the free corrosion potential of TC4 Ti-alloy turns to be higher than that of H62 brass,and the corrosion of the area of H62 brass,where closed to TC4 Ti-alloy is much more severe than that,where far away from the weld seam.The corrosion products of H62 brass after immersion test composed mainly of CuO,Cu2O,CuCl,CuCl2 and Cu(OH)2,while the scale on TC4 Ti-alloy composed mainly of Ti-oxides TiO2 and Ti2O3.The welded couple of H62 brass/TC4 Ti-alloy exhibits galvanic corrosion tendency in 3.5%NaCl solution,and the H62 brass acts as anode in the galvanic couple,which correspondingly underwent accelerated corrosion process.

关 键 词：真空扩散焊接 电偶腐蚀 扫描KELVIN探针 浸泡腐蚀实验 黄铜 Ti 

分 类 号：TG172.5[金属学及工艺—金属表面处理]