激光选区熔化316L不锈钢在酸性氯离子溶液中的钝化行为  

Passivation Behavior of Laser Selective Melted 316L Stainless Steel in Sulphuric Acid Containing Chloride Ion Solution

作　　者：李飞阳 刘志红 乔岩欣[1] 杨兰兰 卢道华 汤雁冰 LI Feiyang;LIU Zhihong;QIAO Yanxin;YANG Lanlan;LU Daohua;TANG Yanbing(School of Materials Science and Technology,Jiangsu University of Science and Technology,Zhenjiang 212003,China;Marine Equipment and Technology Institute,Jiangsu University of Science and Technology,Zhenjiang 212003,China)

机构地区：[1]江苏科技大学材料科学与工程学院,镇江212003 [2]江苏科技大学海洋装备研究院,镇江212003

出　　处：《材料研究学报》2024年第3期221-231,共11页Chinese Journal of Materials Research

基　　金：国家重点研发计划(2018YFC0309100);江苏省重点研发计划重点项目(BE2022062)。

摘　　要：对激光选区熔化316L不锈钢(SLM 316L)进行开路电位、电化学阻抗、动电位极化、恒电位极化、暂态电流-时间测量以及Mott-Schottky、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)和电子背散射衍射(EBSD)等表征,与商用轧制316L不锈钢(R 316L)对比研究其在0.05 mol/L H_(2)SO_(4)+0.2 mol/L NaCl溶液环境中的钝化行为。结果表明:这两种钢钝化膜的形核机制均为连续形核,但是SLM 316L不锈钢的晶粒更小、晶界密度更高、钝化膜生长得更快。SLM 316L不锈钢发生过钝化溶解但是不发生点蚀,而R316L不锈钢发生点蚀。SLM316L不锈钢的耐蚀性能更优,因为其为均一的奥氏体相且有大量的小角度晶界;同时,表面生成的钝化膜中的O^(2-)/OH^(-)比值更低、载流子浓度更低、Cr_(2)O_(3)的含量更高和NiO含量更低,对钝化膜的保护效果更好,使其具有优异的耐点蚀性能。The open-circuit potential,electrochemical impedance spectroscopy,potentiodynamic polarization,potentiostats polarization,current-time transient measurements,Mott-Schottky analysis,X-ray photoelectron spectroscopy(XPS),Electron Back-Scattered Diffraction(EBSD)methods were used to investigate the passivation behavior of 316L stainless steel fabricated by laser selective melted(SLM 316L)in 0.05 mol/L H_(2)SO_(4)+0.2 mol/L NaCl solution.The results were compared with commercial rolled 316L stainless steel(R 316L).The results showed that the nucleation of passivation film follows continuous mechanism for the both stainless steel.However,the SLM 316L stainless steel has smaller grain size and higher grain boundary density than those of R 316L stainless steel.Therefore,the grow rate of passivation film is fast.The SLM 316L stainless steel took place transpassivation dissolution,while R 316L stainless steel took place pitting corrosion.The SLM 316L stainless steel has better corrosion resistance.The main reasons are the SLM 316L stainless steel has much more low angle grain boundaries without ferrite.Moreover,the passivation film of SLM 316L stainless steel has lower carrier density,lower ratio of O^(2-)/OH^(-),lower content of NiO and higher content of Cr_(2)O_(3)compared with R 316L stainless steel.

关 键 词：材料失效与保护 钝化行为 电化学测试 316L不锈钢 

分 类 号：TG172.5[金属学及工艺—金属表面处理]