Effects of chloride ion concentration and pH values on the corrosion behavio of Cr12Ni3Co12Mo4W ultra-high-strength martensitic stainless steel  

作　　者：Hui-yan Li Chao-fang Dong Kui Xiao Xiao-gang Li Ping Zhong 

机构地区：[1]Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China [2]Beijing Institute of Aeronautical Materials, Beijing 100095, China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2016年第11期1286-1293,共8页矿物冶金与材料学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No.51171023);the Fundamental Research Funds for the Central Universities (No.FRF-TP-14-011C1);the Major State Basic Research Development Program of China (No.2014CB643300)

摘　　要：The effects of Cl ion concentration and pH values on the corrosion behavior of Cr12Ni3Co12Mo4W ultra-high-strength martensitic stainless steel（UHSMSS） were investigated by a series of electrochemical tests combined with observations by stereology microscopy and scanning electron microscopy. A critical Cl- ion concentration was found to exist（approximately 0.1wt%）, above which pitting occurred. The pitting potential decreased with increasing Cl- ion concentration. A UHSMSS specimen tempered at 600°C exhibited a better pitting corrosion resistance than the one tempered at 400°C. The corrosion current density and passive current density of the UHSMSS tempered at 600°C decreased with increasing pH values of the corrosion solution. The pits developed a shallower dish geometry with increasing polarization potential. A lacy cover on the pits of the UHSMSS tempered at 400°C accelerated pitting, whereas corrosion products deposited in the pits of the UHSMSS tempered at 600°C hindered pitting.The effects of Cl ion concentration and pH values on the corrosion behavior of Cr12Ni3Co12Mo4W ultra-high-strength martensitic stainless steel（UHSMSS） were investigated by a series of electrochemical tests combined with observations by stereology microscopy and scanning electron microscopy. A critical Cl- ion concentration was found to exist（approximately 0.1wt%）, above which pitting occurred. The pitting potential decreased with increasing Cl- ion concentration. A UHSMSS specimen tempered at 600°C exhibited a better pitting corrosion resistance than the one tempered at 400°C. The corrosion current density and passive current density of the UHSMSS tempered at 600°C decreased with increasing pH values of the corrosion solution. The pits developed a shallower dish geometry with increasing polarization potential. A lacy cover on the pits of the UHSMSS tempered at 400°C accelerated pitting, whereas corrosion products deposited in the pits of the UHSMSS tempered at 600°C hindered pitting.

关 键 词：martensitic stainless steel steel corrosion chloride ions pitting potential 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TG172[金属学及工艺—金属材料]