Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (54권2호 43-52)

Study of High Temperature of Inconel 740 Alloy in Air and Ar-0.2%SO2 Gas

대기 및 Ar-0.2%SO2가스에서 Inconel 740 합금의 고온부식 연구

이동복1,김민정2
Dong Bok Lee1, Min Jung Kim2

1성균관대학교 신소재공학과, 2한국폴리텍대학 신소재응용과
1School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Korea, 2Advanced material application department, Korea Polytechnic College, 478 Munemiro, Bupyeong-gu, Incheo 21417, Korea

DOI : 10.5695/JKISE.2021.54.2.43

Abstract

The Ni-based superalloy, Inconel 740, was corroded between 800 and 1100oC for up to 100 hr in air and Ar-0.2%SO2 gas in order to study its corrosion behavior in air and sulfur/oxygen environment. It displayed relatively good corrosion resistance in both environment, because its corrosion was primarily dominated by not sulfidation but oxidation especially in Ar-0.2%SO2 gas. Such was attributed to the thermodynamic stability of oxides of alloying elements when compared to corresponding sulfides. The scales consisted primarily of Cr2O3, together with some NiAl2O4, MnCr2O4, NiCrMnO4, and rutile-TiO2. Sulfur from SO2 gas made scales prone to spallation, and thicker. It also widened the internal corrosion zone when compared to air. The corrosion resistance of IN740 was mainly indebted to the formation of protective Cr2O3-rich oxides, and suppression of the sulfide formation.

Keywords

Alloys, casting, oxidation, SO2-corrosion, Inconel 74