摘要：对HP40Nb耐热钢行粉末法渗铝，通过改善材料表面的成分和组织，可以提高其在高温和含碳气氛环境下的抗氧化和抗渗碳性能。耐热钢的常规粉末法渗铝往往要在高温下（1000℃以上）通过长时间保温来实现，不仅生产成本高，还会对基体材料组织与性能带来负面影响。本实验对耐热钢表面进行在交流电场作用下的粉末包埋法渗铝研究，优化渗剂配比以及渗铝工艺。粉末包埋法渗铝在700℃-800℃下进行。采用X射线衍射仪分析了渗铝层组织的相成分，并利用显微硬度计对渗铝层的力学性能进行了测试。实验发现，相对于常规的包埋法渗铝，电场增强粉末法渗铝具有更低的外热温度和较快的渗速，可以显著提高实验效率和渗剂的利用率；提高温度，增大交流电场电流可以增加渗铝层的渗速和厚度。

关键词：粉末包埋法渗铝；耐热钢；交流电场

Abstract:The HP40Nb heat-resistant steel’s anti-oxidation property and anti-carburizing property in high temperature and carbon-containing atmosphere environment can be improved by pack aluminizing to improve material’s surface components and structure. The conventional pack aluminizing of heat-resistant steel was carried out by long time thermal retardation at high temperature (above 1000℃) which costs much and has negative impact on matrix material’s structure and properties. Researches were carried out on pack cementation aluminizing by applying AC electric field at heat-resistant steel’s surface, optimizing the mixture ratio of agent and aluminizing process. Pack cementation aluminizing was carried at temperature 700℃ to 800℃。 X ray diffraction and microhardness testing were employed for analyzing the phases and hardness of the aluminizing coating structures respectively. The results showed that compared with conventional pack cementation aluminizing, electric field enhanced pack aluminizing can lowered treating temperature and accelerate infiltrating speed so that can remarkably improve the experimental efficiency and the utilization ratio of agents; the aluminizing coating’s penetrating speed and thickness can be improved by increasing the temperature or increasing the AC field current.

Key words：pack aluminizing；Heat resistant steel ；alternating current field