PTA 공법에 의한 Nimonic 80A 초합금재 Overlay층의 마찰 마모 특성에 관한 연구

Abstract

Wear and corrosion are regarded as both mechanical and chemical damage. Besides that point, these are fatal factor in the operational condition of products .

With the proceeding of the wear and corrosion, the performance of parts is getting lower, and the possibility of the accident increases. Therefore, either repairing the parts or exchanging the damaged parts with the new ones is required.

Regarding repair, surface modification methods as metal spray and overlay welding are generally used. Overlay welding is the way to coats the material on the surface for the purpose of anti-wear, anti-corrosion and heat resisting properties. The various coating way are used to repair the wear parts.

MIG and TIG welding method are commonly used for the purpose of the overlay welding and PTA processing is adopted recently. The PTA processing has high performance compared with other welding ways and its usage is getting expanded due to the development of new machine and controlling technique.

In this study, the MIG welding and PTA processing on Nimonic 80A superalloys are adopted. The purpose of this study is to clarify the microstructure, wear, and erosion properties of the each weld metal.

Following results were obtained from this study :

1. In the MIG welding and PTA processing on Nimonic 80A superalloys, the quality of the overlay layer was different with the overlay coating methode. In case of MIG welding, liquation crack takes place in the base metal, whereas, the liquation crack does not takes place by PTA processing.

2. The wear properties of the Stellite 6 overlay materials show the best performance, whereas Inconel 718 material shows the worst wear properties.

3. In case of the cavitation erosion properties Inconel 625 overlay layers shows the best performance, whereas Stellite 6 are shows the worst erosion properties.