高温碳氢气氛下Cr5Mo钢的尘化腐蚀状况  

Carbonization Corrosion Behavior of Cr5Mo Steel in High-Temperature Hydrocarbon Atmosphere

作　　者：陈成[1,2] 周昌玉[1] 胡桂明[1] 雷娜[1] 

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京210009 [2]广州市特种承压设备检测研究院,广东广州510100

出　　处：《材料保护》2010年第1期65-67,共3页Materials Protection

基　　金：国家自然科学基金(50675096)资助项目

摘　　要：金属渗碳腐蚀(即尘化)是高温碳氢环境下常发生的灾难性腐蚀。Cr5Mo钢的工程应用量大面广,过去对其渗碳腐蚀研究不够。为此,研究了炉管材料Cr5Mo钢在600℃,50%CO-H2-3%H2O气氛下的尘化腐蚀行为,采用X射线衍射分析了腐蚀试样的物相组成,采用扫描电镜对试样进行了微观形貌分析。结果表明:Cr5Mo钢在试验条件下呈现均匀腐蚀,材料自表面向内依次析出Fe5C2和Fe3C脆性腐蚀产物,经560h尘化腐蚀后的试样平均腐蚀深度约为200μm,而基体材料性质无明显改变。因此Cr5Mo钢在尘化过程中出现的腐蚀减薄是由脆性碳化物层的析出引起的。The carbonization corrosion (referring to catastrophic corrosion of Fe-based or Ni-based metals and alloys in high-temperature hy-drocarbon atmosphere,also called metal dusting) behavior of heat-furnace tube material Cr5Mo was evaluated in 50% CO-H2-3 % H2O mixture at 600℃.The chemical composition of the corroded samples was analyzed by using an X-ray diffractome-ter,and the morphology of ihe corroded samples was observed by using a metallographic microscope and a scanning electron micro-scope.Results show that Cr5Mo steel has experienced even corro-sion under the selected testing conditions,which leads to the for-mation of brittle Fe5C2 layer and mixed Fe3C plus Fe from the ex-terior surface to internal matrix.The average corrosion depth of the samples afler 560-hour metal dusting reached to 200μm,but the properties of the metal matrix were hardly changed.This im-plies that the deteriorating and corrosion-induced thinning of the Cr5Mo steel during metal dusting are attributed to the precipitati-on of the brittle carbide layer.

关 键 词：金属渗碳腐蚀 Cr5Mo钢 减薄 表面状态 

分 类 号：TG172.9[金属学及工艺—金属表面处理]