摘要
为了延长奥氏体不锈钢部件在高温环境下的工作寿命,采用电弧喷涂方法在304N不锈钢表面制备45CT/Al复合涂层,对复合涂层试件进行1 100℃×350 h的连续氧化实验,考察其高温氧化行为,通过研究复合涂层的微观组织变化,探索其高温防护机制.实验结果表明,复合涂层以两种方式为304N不锈钢基体提供有效的高温氧化保护.一方面保证在涂层体系中具有足够的Al、Cr元素,在涂层外表面形成以Al2O3为主的氧化物防护层,阻止氧化介质的向内侵入;此外,在复合涂层下的基体金属中形成层状分布的AlN扩散阻挡层,延缓复合涂层体系中Al、Cr抗氧化元素的质量分数减少,使复合涂层保持持久的高温氧化防护能力.
In order to prolong the operating life of austenite stainless steel components at high temperature,a 45CT /Al composite coating was prepared on the surface of 304N stainless steel with the arc spraying method.The continuous oxidation tests for the composite coating were performed at 1 100 ℃ for 350 h,and the high temperature oxidation behavior of coating was investigated.Through studying the microstructure change of composite coating,the high temperature oxidation protection mechanism was clarified.The experimental results show that the composite coating can provide the effective high temperature oxidation protection for 340N stainless substrate in two ways.One way is that enough Cr and Al elements are guaranteed in the coating system,and the protective oxide film mainly composed of Al2O3forms on the external surface of coating,which can prevent the inward invasion of oxidation medium.The other way is that the layer-like AlN diffusion barrier layer is generated in the substrate metal under the composite coating,and can delay the concentration reduction of such anti-oxidation elements as Cr and Al in the composite coating system,which can make the composite coating maintain a long-term effective protection ability.
出处
《沈阳工业大学学报》
EI
CAS
北大核心
2014年第4期384-389,共6页
Journal of Shenyang University of Technology
基金
国家自然科学基金资助项目(51301112)
关键词
高温氧化
电弧喷涂
复合涂层
防护机制
扩散阻挡层
奥氏体不锈钢
high temperature oxidation
arc spraying
composite coating
protective mechanism
diffusion barrier layer
austenite stainless steel
