摘要
为提高0Cr18Ni10Ti不锈钢的抗高温氧化能力,采用熔剂法在0Cr18Ni10Ti不锈钢表面制备热浸镀铝层,并经950℃、2 h高温扩散。采用SEM、EDS对热浸镀铝高温扩散试样及不锈钢试样900℃氧化不同时间的表面、截面进行了形貌观察及成分分析。结果表明:镀铝高温扩散试样的氧化动力学曲线较平缓且氧化增重较小;0Cr18Ni10Ti不锈钢经900℃、100 h氧化后表面主要由Fe2O3组成,氧沿晶界向内扩散产生内氧化;镀铝高温扩散试样900℃氧化期间,表面主要由Al2O3氧化膜组成,有效地阻止了合金元素与氧的互扩散,Ni元素在Fe Al层与Al固溶层富集阻碍了Fe Al合金层Al向基体扩散,使镀铝高温扩散试样Fe Al合金层经900℃、100 h氧化后Al元素贫化量较少。镀铝高温扩散试样900℃、100 h下的抗氧化性能优于0Cr18Ni10Ti不锈钢。
Hot-dipping Al coating was prepared on the surface of 0Cr18Ni10 Ti stainless steel by hot-dipping in a molten aluminum bath.Resultant Al coating was then diffusion-annealed at 950℃ for 2 h to afford high temperature diffused layer.The surface and cross- section morphologies as well as the composition of the hot-dipping Al/diffused layer after oxidation tests at 900 ℃ for different durations were analyzed by scanning electron microscopy and energy dispersive spectrometry.Results indicated that 100 h oxidation of the stainless steel substrate under 900℃ led to Fe_2O_3 on the surface,and O tended to be diffused towards the steel substrate thereby causing inner oxidation.However,the oxidation of the hot- dipping Al/diffused layer under the same conditions generated Al_2O_3 layer on the surface,thereby effectively inhibiting the mutual diffusion of the alloying elements and O.Besides,Ni was enriched in the FeAl layer and Al solid solution layer,thereby inhibiting the diffusion of Al in FeAl alloy layer onto the steel substrate and reducing the depletion amount of Al element during the high- temperature oxidation process.In one word,the isothermal oxidation kinetic curve of the hot-dipping Al/diffused layer was of a relatively small slope as well as oxidation weight gain,which meant it exhibited much better high- temperature oxidation resistance than the stainless steel substrate.
出处
《材料保护》
CAS
CSCD
北大核心
2015年第1期14-16,23,共4页
Materials Protection
基金
江西省自然科学基金项目(20122BAB206012)
校级科研项目(KY2011zz03)资助
关键词
热浸镀铝
高温扩散
0CR18NI10TI
高温氧化行为
hot-dipping aluminum
high temperature diffusion
0Cr18Ni10Ti stainless steel
high-temperature oxidation behavior
