摘要
双相不锈钢中的铁素体(α相)和奥氏体(γ相)具有不同的晶体结构和化学成分,使之在水溶液环境中表现不同的耐蚀特征.本文应用空间分辨电化学技术测量2205双相不锈钢中铁素体和奥氏体的电位差异,并用电镜技术分析了α相和γ相的选择性腐蚀形态.结果表明,在0.01mol/LNaCl溶液中,铁素体的腐蚀电位比奥氏体高,而在2mol/LH2SO4+xmol/LHCl溶液中,双相不锈钢在活化＿钝化电位区出现两个明显的阳极电流峰.铁素体相的选择性腐蚀发生在较负的阳极峰电位,而奥氏体则在较正的阳极电位峰发生选择性腐蚀.
In duplex stainless steel, the two constituent phases, namely ferritic (α)and austenitic(γ) phases, have different crystal structure and chemical composition. They may thus exhibit different corrosion resistances in aqueous environment. In this investigation, an electrochemical technique with spatial resolution was employed to measure the potential difference between these two constituent phases in 2205 duplex stainless steel. Image analyzing techniques were also used to examine the preferential corrosion between α and γ phases. The experimental results showed that ferrite had a higher potential than austenite in0.01 mol/L NaCl solution. In 2 mol/L H2SO4+x mol/L HCl solution, two distinct peaks appeared in the anodic polarization curve in the passive_to_active transition region. Preferential corrosion occurred in the ferrite phase at a lower anodic peak potential, while in austenite at a higher anodic peak potential.
出处
《电化学》
CAS
CSCD
2003年第2期170-176,共7页
Journal of Electrochemistry
基金
SCC and NNSFC for supporting the work under contract NSC89-2216-E-006-068 and 20127302.
