In this paper, the experiment was carried out to study the cementation phenomenon of aluminium into steel surface by diffusion heat treatment after aluminium coating onto the steel plate by arc spray method. Variation of metallurgical and mechanical properties of cementation layer were inspected in various heat treatment conditions. It IS clarified that the coating film which has excellent erosion resistance and high temperature oxidation resistance can be obtained by the process presented in this study.

1. Introduction

As the environment used becomes severe, the superior materials that have the surface properties such as heat resisting, corrosion resisting and wear resisting have been more greatly needed in service. To meet this need, the spray methods that are the surface coating techniques of the higher grade materials on the surface of the lower grade materials are highlighted lately. Among these, arc spray method that employs a electrical arc as a heat source has been widely used, because of convenience of operating and low cost of apparatus. In this metal arc spray method, however, it is pointed out that the erosion properties of the sprayed components are of poor quality when it is used in severe environments such as corrosion, high temperature and friction, due to the low adhesive strength between coating film and the substrate. To overcome these problems, technique or method to Improve the adhesive strength must be settled. (Kawase, Kusalshl and Maebara, 1984, Ishikawa and Sekl, 1979) On the other hand, metal cementation methods such as sheradizing, chromizing are adequate to make the superior coated layer onto substrate, while their process IS very complicate (Kang and Yeo, 1986) In this study, the experiment was carried out to establish aluminium cementation technique to steel surface by diffusion heat treatment after coating aluminium onto substrate by arc spray method.

This content is only available via PDF.
You can access this article if you purchase or spend a download.