2205双相不锈钢在熔融氯化物盐膜下的腐蚀

Corrosion of 2205 Duplex Stainless Steel under the Presence of Chloride Deposit at 450℃

利用热重分析考察了表面涂有ZnCl2-KCl混合盐膜的2205双相不锈钢在450℃氧化性气氛中的耐蚀性。结果表明,材料发生加速腐蚀,形成厚且疏松的表面腐蚀层,并在基体内发生晶间腐蚀及沿富Cr相的择优侵蚀。在该环境下,材料中较高的Cr含量没有提供充分的保护性,甚至恶化材料的耐蚀性能,用热力学讨论其作用机理。

The corrosion resistant behavior of one 2205 duplex stainless steel was examined beneath ZnCl2KCl salt film in pure oxidizing environment at 450℃ An accelerated corrosion is observed due to the formation of porous and nonprotective corrosion products Intergranular corrosion and preferential attack along the chromiumrich phase induced by chlorine is also observed inside the matrix as well as the general corrosion Cr can hardly provide any effective protection and even worsen the corrosion resistance of the alloy against such corrosive environment, and the mechanism is discussed based on thermodynamics