Effects of rare earth modifying inclusions on the pitting corrosion of 13Cr4Ni martensitic stainless steel  

作　　者：Changgang Wang Rongyao Ma Yangtao Zhou Yang Liu Enobong Felix Daniel Xiaofang Li Pei Wang Junhua Dong Wei Ke 

机构地区：[1]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Environmental Corrosion Centre of Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China

出　　处：《Journal of Materials Science & Technology》2021年第34期232-243,共12页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.51801219);the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2019193);the Scientific Research Project of China Three Gorges Corporation(No.JD-YJ-05006);the National Key Research and Development Program of China(No.2017YFB0702302)。

摘　　要：In this study,the pitting corrosion behavior of 13Cr4Ni martensitic stainless steel(BASE)and that modified with rare earth(REM)in 0.1 mol/L Na Cl solution were characterized.Techniques such as automatic secondary electron microscope(ASPEX PSEM detector),scanning electron microscope(SEM),transmission electron microscope(TEM),scanning Kelvin probe force microscope(SKP),potentiodynamic and potentiostatic polarizations were employed.The results obtained indicate that BASE steel contains Al_(2)O_(3)/Mn S,Al_(2)O_(3) and Mn S inclusions,while REM steels contain(La,Ce,Cr,Fe)-O and(La,Ce,Cr,Fe)-O-S inclusions.Compared with BASE steel,REM steel is more susceptible to induce the metastable pitting nucleation and repassivation,whereas it restrains the transition from metastable pitting to stable pitting.Adding 0.021%rare earth element to BASE steel can reduce the number and area of inclusions,while that of 0.058%can increase the number and enlarged the size of inclusions,which is also the reason that pitting corrosion resistance of 58 REM steel is slightly lower than that of 21 REM steel.In the process of pitting corrosion induced by Al_(2)O_(3)/Mn S inclusions,Mn S is preferentially anodic dissolved,and also the matrix contacted with Al_(2)O_(3) is subsequently anodic dissolved.For REM steels,anodic dissolution preferentially occurs at the boundary between inclusions and matrix,while(La,Ce,Cr,Fe)-O inclusions chemically dissolve in local acidic environment or are separated from steel matrix.The chemically dissolved substance(La^(3+) and Ce^(3+))of(La,Ce,Cr,Fe)-O inclusions are concentrated in pitting pits,which inhibits its continuous growth.

关 键 词：13Cr4Ni martensitic stainless steel Rare earth modifying inclusion Al_(2)O_(3)/MnS inclusion Metastable pitting corrosion Stable pitting corrosion 

分 类 号：TG142.71[一般工业技术—材料科学与工程]