熔盐电解共渗铝硅及渗层的抗高温腐蚀性能

在渗铝涂层中加入少量硅可进一步提高涂层的抗高温氧化和热腐蚀性能。本文作者采用一种新的方法—高温熔盐电解法,在熔融氯化物盐浴中进行电解共渗铝硅,在铁和铁—铬合金上获得了渗铝硅涂层。 用氯化物作为电解质主要优点是无毒和价廉。高温熔盐电解渗铝硅可获得表面光洁、厚度均匀、与基体结合良好的致密渗层。通过控制电解温度、时间和电流密度可容易地控制渗层厚度,所得到的渗层不需随后热处理。 1000℃氧化试验和900℃热腐蚀(盐膜法)结果表明渗铝硅涂层比单纯渗铝涂层具有更好的保护性能。

FUSED SALT ELECTROLYTIC CO-DEPOSITION OF Al AND Si AND HIGH TEMPERATURE CORROSION RESISTANCE OF Si-CONTAINING ALUMINIUM COATINGS

Aluminium coatings are the most widely used high temperature protective coatings. A small amount of Si can be added in aluminium coatings to further improve the resistance to high temperature corrosion. At present, pack cementation, slurry coating and hot dipping are generally adopted to produce Al and Al-Si coatings. In this work, Si-containing aluminium coatings on Fe and Fe-Cr alloys are made by electrolytic codeposition of Al and Si from fused chloride bath. Smooth, adherent and dense coatings can be produced by fused salt electrolytic co-deposition of Al and Si. The coatings are uniform in thickness which can easily be controlled by the process parameters, such as temperature, time and current density. No subsquent heat treatment is needed after coating. The results of oxidation test at 1000~C and hot corrosion test(using salt-film method) at 900℃ show that Si-containing aluminium coatings have better protective properties then plain aluminium coatings.