激光表面处理对316L奥氏体不锈钢耐腐蚀性能的影响  

Effect of Laser Surface Treatment on the Corrosion Resistance of 316L Stainless Steel

作　　者：袁珊珊 王东哲 王金太 王春光 何曲波 蔡欣男 胡伟 YUAN Shan-shan;WANG Dong-zhe;WANG Jin-tai;WANG Chun-guang;HE Qu-bo;CAI Xin-nan;HU Wei(Chongqing Key Laboratory of Corrosion-resistant Alloys,Chongqing Materials Research Institute Co.,Ltd,Chongqing 400707,China;National Engineering Research Center for Instrument Functional Materials,Chongqing Materials Research Institute Co.,Ltd,Chongqing 400707,China)

机构地区：[1]重庆材料研究院有限公司耐腐蚀合金重庆市重点实验室,重庆400707 [2]重庆材料研究院有限公司国家仪表功能材料技术研究中心,重庆400707

出　　处：《表面技术》2021年第7期83-89,共7页Surface Technology

基　　金：国家科技重大专项(2017ZX06004004);中国机械工业集团有限公司重大科技专项(SINOMAST-ZDZX-2019-03)。

摘　　要：目的研究退火态和变形态不锈钢基体在激光加工时组织结构和耐腐蚀性能的差异,掌握激光功率对材料表面耐腐蚀性能的影响规律。方法利用Nd:YAG激光处理,对不同热处理状态的316L奥氏体不锈钢进行了一系列激光表面熔凝处理。运用电子通道衬度成像(ECC)对激光表面处理前后的组织结构进行了详细地表征和分析,采用Gamry600电化学工作站对改性表面进行极化曲线、交流阻抗图谱检测,从而研究激光处理对材料表面耐腐蚀性的影响。结果退火态和变形态的316L奥氏体不锈钢经过激光处理后,在3.5%NaCl溶液中测试的动电位极化曲线和阻抗图谱趋势相近。拟合数据显示,退火态基体经激光处理后,腐蚀电位为-0.438 V(SCE),略高于初始样品(-0.556 V),且腐蚀电流比初始样品小,表明激光处理能够降低材料表面的腐蚀速度。不同之处在于,变形态基体的表面改性区界面过渡均匀,无突变组织,呈现更加良好的结合性。随着激光功率的增大,功率400W处理样品的熔抗弧半径最大,但自腐蚀电流和电位与200 W和300 W处理样品在同一数量级波动。结论 316L奥氏体不锈钢经过激光表面处理后,耐腐蚀性能得到一定程度的改善,而激光功率对表面耐腐蚀性无明显关联性影响。The difference of microstructure and corrosion resistance of annealed and variable shape stainless steel matrix during laser processing was studied,master the influence law of laser power on the corrosion resistance of material surface.Laser surface melting treatment using Nd:YAG was done with 316L stainless steel at different heat treatment conditions,electron channeling contrast imaging(ECC)was employed to characterize and analyze the microstructure,and Gamry600 electrochemical workstation was used to experiment the polarization curve and impedance diagram for the sake of studying corrosion resistance evolution during laser surface treatment.316L stainless steels at annealing condition and deformation condition have similar dynamic potential polarization curve and EIS maps tendency in 3.5wt%NaCl solution.Meanwhile,the fitting data indicated that corrosion potential of laser sample was−0.438 V(SCE),slightly higher than as-received sample(−0.556 V),but the corrosion current of the laser sample was smaller than that of the as-received sample.It means that laser surface treatment could reduce the corrosion rate of the material surface.The difference is the modification zone on as-draw matrix presented uniform interfacial transition and better binding property than annealing samples.With laser power increasing,the melting arc radius of the 400 W sample was largest,then the polarization curve and EIS map fluctuated in the same magnitude on 200 W and 300 W samples.The corrosion resistance of 316L stainless steel has gradually enhanced after laser surface treatment,while the laser power has no obvious effect on the surface corrosion resistance.

关 键 词：激光表面处理 奥氏体不锈钢 耐腐蚀性能 热处理状态 

分 类 号：TG174.4[金属学及工艺—金属表面处理]