摘要
采用不连续增重法研究了Re对一种镍基单晶高温合金1000℃恒温氧化行为的影响,采用扫描电镜(SEM)和X射线衍射分析仪(XRD)对样品的组织进行了观察。结果表明,两种合金生成的氧化膜成分相似,都生成了以含Cr、Ti氧化物为主的外氧化层、Al_2O_3内氧化层以及含有TiN的内氮化层。但二者氧化速率及氧化层结构存在较大差异,含Re合金的氧化速率较慢,Al_2O_3层较完整且TiN数量较少。Re的作用机理在于它提高了合金中Cr的活度,增大氧化膜中Cr_2O_3的含量,加快Al的选择性氧化,促进合金氧化膜内部连续Al_2O_3层的形成,抑制合金内部氮化物的生成,提高长期氧化下氧化膜的稳定性。
Effect of rhenium（Re） addition on isothermal oxidation behavior of a nickel-base single crystal superalloy was investigated by means of intermittent measurement of weight change as well as scanning electron microscope（SEM） and X-ray diffractometer（XRD）. It was shown that, a scale composed of a（Cr, Ti）-enriched outer oxide layer, an inner Al2O3 layer and an inner TiN layer was formed for both the Re-containing and Re-free alloys, however, the Al2O3 layer was much more complete and the amount of TiN was much less on the Re-containing alloy rather than those on the Re-free alloy. Re was found to lower the oxidation rate of the alloy and improve the stability of the entire oxide scale during longterm oxidation by increasing the activity of Cr and thus increasing the content of Cr2O3 in the scale. Enhancement of Cr2O3 formation may then accelerate the selective oxidation of Al and thus promote the formation of a continuous Al2O3 layer beneath the outer oxide scale, as a result, which inhibited the formation of the inner nitride.
作者
常剑秀
王栋
董加胜
王迪
吴汉昌
张功
楼琅洪
CHANG Jianxiu WANG Dong DONG Jiasheng WANG Di WU Hanchang ZHANG Gong LOU Langhong(College of Materials Science and Engineering, Xi＇an Shiyou University, Xi＇an 710065, China Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China Guiyang AECC Power Investment Casting Ltd. Co., Guiyang 550014, China)
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2017年第9期695-702,共8页
Chinese Journal of Materials Research
基金
国家自然科学基金(51631008)
国家重点研发计划(2016YFB0701403)~~
关键词
金属材料
镍基单晶高温合金
高温氧化
RE
活度
选择性氧化
metallic materials, nickel-base single crystal superalloy, high temperature oxidation, rhe-nium （Re）, activity, selective oxidation
