NiCr合金在含氯氧化性气氛中的高温腐蚀

High Temperature Corrosion of NiCr Alloys in Chlorination-oxidation Atmosphere

研究了纯Ni以及不同Cr含量的NiCr合金在5％O2-O.3％HCl-N2(体积分数)气氛中800℃的腐蚀行为,结果表明:在氧化膜／基体金属界面处有氯化物生成,合金的加速腐蚀机制为氯参与的"活化腐蚀"过程。NiCr合金在腐蚀初期表现为失重与生成Cr的氯化物和氯氧化物的挥发性有关,但Cr依然有益于合金的抗氯化-氧化腐蚀性。

Corrosion behavior of pure Ni and three NiCr alloys were studied in 5%O2-0.3%HCl-N2 (volume fraction) at 800°C. The results show that all of materials undergo accelerating corrosion and metal chlorides form at the interface of oxide scale/metal substrate. NiCr alloys suffered mass loss in initial stage of corrosion, which may be caused by sublimation of chromium of chlorides and oxychlorides. However, addition of Cr in NiCr alloys can improve their corrosion resistance in the mixed atmosphere.