Effect of Surface Treatment on High-Temperature Oxidation Behavior of IN 713C

TL;DR

This study investigates how different surface treatments affect the high-temperature oxidation behavior of IN 713C, revealing that grinding improves oxidation resistance by promoting protective alumina scale formation.

Contribution

It introduces a model based on the generalized Darken method to explain the oxidation mechanisms influenced by surface defects and treatments.

Findings

Ground samples show lower oxidation rates than polished ones.

Grinding induces defects that enhance alumina scale formation.

A new oxidation mechanism model at lower temperatures is proposed.

Abstract

The effects of surface preparations on oxidation kinetics and oxide scale morphology for the commercially available Ni-based superalloy IN 713C have been investigated. The ground and polished samples were exposed in air at 800-1100C. The ground specimens were found to demonstrate lower oxidation kinetics compared to those after polishing. The grinding also affected the oxide scale morphology, resulting in a protective alumina scale, while the polished samples developed Ni-/Cr-rich mixed oxides on the surface. Better oxidation resistance of the ground surfaces is related to a higher concentration of defects in the nearsurface region introduced by cold working. These defects facilitate the outward transport of the scaleforming element Al and thus are beneficial for protective oxidation. The oxidation mechanism at lower temperatures was introduced. The model based on the generalized Darken method and multiphase approximation was proposed.