SLM成形GH4169合金耐高pH值溶液腐蚀性能分析  

Corrosion Resistance of SLM Formed GH4169 Alloy to High pH Solution

作　　者：王丽娟 董慧锋 韦翠翠 张明[2] Wang Lijuan;Dong Huifeng;Wei Cuicui;Zhang Ming(School of Mechanical and Electrical Engineering,Zhengzhou Institute of Industrial Application Technology,Zhengzhou,Henan 451100,China;Schoo of Mechanical Engineering,Henan Polytechnic University,Jiaozuo,Henan 454000,China)

机构地区：[1]郑州工业应用技术学院机电工程学院,河南郑州451100 [2]河南理工大学机械工程学院,河南焦作454000

出　　处：《应用激光》2022年第8期81-87,共7页Applied Laser

基　　金：河南省科技攻关项目(182102210556)。

摘　　要：为了提高传统轧制(R)态R-GH4169合金的耐腐蚀特性,采用选区激光熔覆(SLM)方式制备得到S-GH4169合金。配制pH=13B的腐蚀溶液,并通过试验测试的手段分析了合金耐腐蚀性能以及腐蚀生成的钝化膜性能。研究结果表明,S-GH4169合金内形成了大量弧形熔池,观察到枝状晶与胞状晶;R-GH4169合金是等轴晶组织,晶粒尺寸接近20μm。S-GH4169合金获得了比R-GH4169合金更高的开路电压,耐腐蚀能力更强的钝化层,使得钝化电流密度大幅增加,获得宽度更大的容抗弧,显著提升了抗腐蚀能力。在最初100 s时间内已在表面生成钝化膜结构,但总体上钝化膜厚度呈现持续增大的变化规律。S-GH4169合金在钝化膜中形成了更少的载流子,有效增强了钝化膜保护作用。该研究为评价碱性条件下的S-GH4169合金耐腐蚀性能提供了参考依据。To improve the corrosion resistance of conventional rolled R-GH4169 alloy,S-GH4169 alloy was prepared by laser cladding(SLM).After being treated by corrosion solution of pH=13 B,the corrosion resistance of the alloy and the passivation film produced by the corrosion were analyzed by experimental test.The results show that a large number of arc-shaped molten pools are formed in S-GH4169 alloy,and dendritic and cellular crystals are observed.R-GH4169 alloy shows equiaxed grain structure with grain size approaching to 20μm.Compared with R-GH4169 alloy,S-GH4169 alloy can endure higher open circuit voltage,the passivation layer with stronger corrosion resistance greatly increases the passivation current density and obtains the capacitive arc with larger width,which significantly improves the corrosion resistance ability.With the first 100 s of experiment,the passivated film structure has been formed,and the thickness of passivated film shows a continuous increase in general.There are fewer carriers in the passivation film of S-GH4169 alloy,which effectively enhances the protective effect of the passivation film.This study provides a reference for evaluating the corrosion resistance of S-GH4169 alloy under alkaline conditions.

关 键 词：GH4169合金 激光选区熔化 钝化膜 碱性溶液 

分 类 号：TG172[金属学及工艺—金属表面处理]