磷酸盐-柠檬酸盐体系中Q235钢焊接接头磷化处理及耐蚀性  

Phosphating treatment and corrosion resistance of Q235 steel welded joint in phosphate-citrate phosphating solution system

作　　者：于瑾佳[1] 王琳[2] Yu Jinjia;Wang Lin(Hebei Energy College of Vocation and Technology,Tangshan 063000,China;Tangshan College,Tangshan 063000,China)

机构地区：[1]河北能源职业技术学院,河北唐山063000 [2]唐山学院,河北唐山063000

出　　处：《电镀与精饰》2023年第2期42-48,共7页Plating & Finishing

基　　金：唐山市应用研究基础创新团队资助项目(18130217A)。

摘　　要：将柠檬酸钠添加到锌锰系磷化液中配成磷酸盐-柠檬酸盐磷化液体系,然后在该体系中对Q235钢焊接接头进行磷化处理。研究了磷化液体系中柠檬酸钠的质量浓度对Q235钢焊接接头表面磷化膜的微观形貌、成分、厚度和耐蚀性的影响。结果表明:磷化处理后焊接接头的外观呈黑灰色,磷化膜完整地覆盖母材和焊缝区域并且结合紧密。随着柠檬酸钠质量浓度的增加,磷化膜的微观形貌发生明显变化,厚度呈先增加后降低的趋势,导致耐蚀性先提高后下降。柠檬酸钠的质量浓度为2.5 g/L时获得的磷化膜表面结构较致密且厚度最大(约9.4μm),其腐蚀电流密度为1.36×10^(-6)A/cm^(2)且耐点滴时间达到186 s,可以起到较理想的防护作用。在此条件下磷化处理后的Q235钢焊接接头表现出良好的耐蚀性。Sodium citrate was added into zinc-manganese phosphating solution to prepare the phosphate-citrate phosphating solution system,and then Q235 steel welded joint was phosphated in this system.The effects of the mass concentration of sodium citrate in the phosphating solution system on the morphology,composition,thickness and corrosion resistance of the phosphating film on Q235 steel welded joint were studied.The results showed that the appearance of the welded joint after phosphating treatment was black and gray,and the base metal and weld area were completely covered and closely combined by the phosphating film.With the increase of the mass concentration of sodium citrate,the morphology of the phosphating film changed significantly,and the thickness increased first and then decreased,resulting in the corrosion resistance improved first and then declined.When the mass concentration of sodium citrate was 2.5 g/L,the surface of as-prepared phosphating film was dense and the thickness was the largest(about 9.4μm),the corrosion current density was 1.36×10^(-6)A/cm^(2) and the time of drip resistance was 186 s,which can play an ideal protective effect.The Q235 steel welded joint exhibited excellent corrosion resistance after phosphating treatment under this condition.

关 键 词：Q235钢焊接接头 磷酸盐-柠檬酸盐体系 磷化处理 柠檬酸钠 耐蚀性 

分 类 号：TG174[金属学及工艺—金属表面处理]