Carbide free nano-bainitic (NSB) steels have a dual phase structure comprising of retained austenite (RA) and bainitic ferrite (BF). The content and morphology RA and BF in NSB steels can be easily modulated by changing the austempering temperature. This results in significant changes in the strength and is expected to influence the corrosion resistance as well. The corrosion behavior of three NSB steel blocks austempered at 250, 300 and 350 °C has been studied in aqueous chloride (3.5 wt% NaCl) environment. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization have been used to investigate the role of austempering temperature on the corrosion response. It is found that the corrosion current density and hence the corrosion rate decreases with a reduction in austempering temperature. Moreover, a reduction in the austempering temperature shifts the corrosion potential towards the nobler side. The EIS studies have shown that the charge transfer resistance ge...

中文翻译：

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在不同温度下回火制备的纳米结构贝氏体钢在氯化物环境中的比较电化学阻抗谱研究

无碳化物纳米贝氏体（NSB）钢具有由残余奥氏体（RA）和贝氏体铁素体（BF）组成的双相结构。改变奥氏体化温度可以很容易地调节NSB钢中RA和BF的含量和形貌。这会导致强度发生重大变化，并且预计也会影响耐蚀性。已经研究了三种NSB钢块在250、300和350°C的温度下在氯化物水溶液（3.5 wt％NaCl）中的腐蚀行为。电化学阻抗谱（EIS）和电势极化已用于研究奥氏体温度对腐蚀响应的作用。发现随着奥氏体回火温度的降低，腐蚀电流密度以及腐蚀速率降低。此外，奥氏体温度的降低将腐蚀电位移向了更高的一侧。EIS研究表明，电荷转移电阻会降低。