Micro-electrochemical insights into pit initiation site on aged UNS S32750 super duplex stainless steel
Micro-electrochemical insights into pit initiation site on aged UNS S32750 super duplex stainless steel
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DOI：
10.1038/s41529-023-00335-8
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发表时间：
2023-03
影响因子：
5.1
通讯作者：
Shuichiro Amatsuka;M. Nishimoto;I. Muto;Makoto Kawamori;Yuya Takara;Y. Sugawara
中科院分区：
文献类型：
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作者：
Shuichiro Amatsuka;M. Nishimoto;I. Muto;Makoto Kawamori;Yuya Takara;Y. Sugawara
UNS S32750超级双相不锈钢在1173 K、1.0 ks时效处理后，在α、γ相界区产生σ相和二次奥氏体（γ2）相。钢中存在少量Mn-Cr氧化物和MnS复合夹杂物。在348 K下，在1 M MgCl 2中，在不含夹杂物的小区域（200 × 200 µm）的动电位极化过程中未观察到点蚀。由于电极区含有α、γ、σ和γ 2相，这些相及其边界不能单独作为点蚀的起始点。电极面积从3 × 3 mm逐渐减小到1 × 1 mm，在靠近σ相的γ 2相区域观察到Mn-Cr氧化物和MnS复合夹杂物发生点蚀。
An aging treatment of UNS S32750 super duplex stainless steel at 1173 K for 1.0 ks produced σ and secondary austenite (γ2) phases in the α and γ phase boundary regions. Small amount of Mn-Cr oxide and MnS complex inclusions were present in the steel. No pitting was observed during the potentiodynamic polarization of a small area (200 × 200 µm) without inclusions in 1 M MgCl2at 348 K. Because the electrode area included α, γ, σ, and γ2phases, these phases and their boundaries alone could not act as initiation sites for pitting. The electrode area size was gradually reduced from 3 × 3 mm to 1 × 1 mm, and pitting corrosion was observed to occur at the Mn-Cr oxide and MnS complex inclusions in a region that appeared to be the γ2phase near the σ phase.