Morphological Development of Subscale Formation in Fe–Cr–(Ni) Alloys with Chloride and Sulfates Coating

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• 作者：Wang ; Chaur Jeng ; He ; Tien Tsuo
• 关键词：hot corrosion ; stainless steel ; NaCl ; AlCl3 ; Al2(SO4)3
• 刊名：Oxidation of Metals
• 出版年：2002
• 出版时间：2002
• 年：2002
• 卷：58
• 期：3/4
• 页码：415-437
• 全文大小：2.29 MB

文摘

Three types of stainless steel (430, 304, and 310) with a coating of NaCl, NaCl/AlCl₃, or NaCl/Al₂(SO₄)₃ are exposed at 750 and 850°C. Results show that NaCl has a major effect on corrosion and sulfur plays an important role in intergranular corrosion. After high-temperature exposure with a 100 % NaCl coating, the morphologies of alloys 304 and 310 show typical uniform subscale attack the depths of attack increasing with temperature, while alloy 430 showed a planar attack. Alloy 310 has the highest chromium content and has the least metal loss. After high-temperature exposure with a NaCl/AlCl₃ coating, the corrosion morphologies and depths of attack are similar to those associated with an NaCl coating, but only voids are larger in the subscale. When coated with NaCl/Al₂(SO₄)₃, the alloys are attacked simultaneously by sulfur and chlorine at 750°C, resulting in a typical sulfur-attack intergranular corrosion. However, as the temperature increases to 850°C, the corrosion morphology changes to a uniform subscale attack.