Abstract The nucleation and growth of pitting corrosion in grade 2202 lean duplex stainless steel has been observed via X-ray Computed Tomography. The charge measured using an electro-chemical in-situ cell was correlated with pit growth characteristics and associated pit shape morphologies. Lacy metal covers were observed with holes formed by selective dissolution of the ferrite. All pits grew into semi-ellipsoid shapes, with large fractions of un-dissolved austenite grains remaining inside pits in heat-treated microstructures. For the as-received microstructure the stability product showed typical values below 0.3 Am−1, with larger stability values observed for the heat-treated sample.

中文翻译：

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精益双相不锈钢点蚀的 X 射线断层扫描表征

摘要 通过 X 射线计算机断层扫描观察了 2202 级贫双相不锈钢中点蚀的形核和生长。使用电化学原位电池测量的电荷与凹坑生长特征和相关凹坑形状形态相关。观察到花边金属覆盖物具有通过铁氧体选择性溶解形成的孔。所有的凹坑都长成半椭圆形，在热处理的微观结构中，大部分未溶解的奥氏体晶粒留在凹坑内。对于原样的微观结构，稳定性乘积显示出低于 0.3 Am-1 的典型值，热处理样品的稳定性值更大。