金属热处理 ›› 2021, Vol. 46 ›› Issue (11): 207-212.DOI: 10.13251/j.issn.0254-6051.2021.11.037

• 表面工程 • 上一篇    下一篇

K438铸造高温合金表面热浸镀铝涂层的抗氧化性能

邓鹏飞1, 左林春1, 陈星伟1, 熊伟1, 刘艳1, 廖从来2, 李智1   

  1. 1.湘潭大学 材料科学与工程学院, 湖南 湘潭 411105;
    2.湖南江滨机器集团有限责任公司, 湖南 湘潭 411105
  • 收稿日期:2021-08-21 出版日期:2021-11-25 发布日期:2021-12-08
  • 通讯作者: 李 智,教授,博士,E-mail:lizhiclsj@163.com
  • 作者简介:邓鹏飞(1996—),男,硕士研究生,主要研究方向为金属材料表面处理,E-mail:373318021@qq.com
  • 基金资助:
    国家自然科学基金(51971189);湖南省自然科学基金株洲联合基金(2019JJ60011);湘潭大学生创新训练项目

Oxidation resistance of hot-dip aluminized coating on cast K438 superalloy

Deng Pengfei1, Zuo Linchun1, Chen Xingwei1, Xiong Wei1, Liu Yan1, Liao Conglai2, Li Zhi1   

  1. 1. School of Materials Science and Engineering, Xiangtan University, Xiangtan Hunan 411105, China;
    2. Hunan Jiangbin Machinery (Group) Co., Ltd., Xiangtan Hunan 411105, China
  • Received:2021-08-21 Online:2021-11-25 Published:2021-12-08

摘要: 针对K438镍基高温合金在高温条件下抗氧化性能不足的问题,采用热浸镀铝技术在其表面制备了铝化物涂层。经1000 ℃、1 h真空扩散退火处理后,对高温合金的热浸镀铝涂层开展了1000 ℃、250次的高温循环氧化试验,并采用扫描电镜、能谱仪、X射线衍射仪等分析测试手段,对高温氧化后涂层截面组织进行了研究。结果表明,试验合金在1000 ℃、40次循环氧化后氧化增量曲线便开始下降,高温抗氧化性能较差,经1000 ℃、250次循环氧化后,形成了Al2O3、TiO2、Cr2O3、NiO和尖晶石NiCr2O4、NiAl2O4等氧化产物。而热浸镀铝涂层经1000 ℃、40次循环氧化后,氧化增量变化较小,且经250次循环氧化后,氧化产物中未发现Cr2O3的存在,其高温抗氧化性能均较基体明显提高,其中热浸镀90 s的涂层高温抗氧化性能更好。

关键词: K438高温合金, 热浸镀铝, 防护涂层, 循环氧化

Abstract: In view of the insufficient oxidation resistance of K438 nickel-based superalloy at high temperature, the aluminized coating was prepared on its surface by hot dip aluminizing technology. After vacuum diffusion annealing treatment at 1000 ℃ for 1 h, the high temperature cyclic oxidation tests at 1000 ℃ for 250 cycles were carried out on the superalloy with hot-dip aluminized coating. The cross-sectional microstructure of the coatings after high temperature oxidation was studied by means of scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD). The results show that the oxidation mass gain curve of the substrate alloy begins to decline after oxidation at 1000 ℃ for 40 cycles, and the oxidation resistance at high temperature is poor, and the oxidation products such as Al2O3, TiO2, Cr2O3, NiO and spinel NiCr2O4, NiAl2O4 are formed after oxidation at 1000 ℃ for 250 cycles. However, the oxidation mass gain changes a little after oxidation at 1000 ℃ for 40 cycles, the Cr2O3 is not found in the oxidation products of hot-dip aluminized coatings after oxidation at 1000 ℃ for 250 cycles, and its high temperature oxidation resistance is significantly higher than that of the substrate alloy, among which the coating hot-dip aluminized for 90 s has better oxidation resistance at high temperature.

Key words: K438 superalloy, hot-dip aluminizing, protective coating, cyclic oxidation

中图分类号: