THE OXIDATION RESISTANCE OF HIGH ALUMINUM HEAT RESISTANT STEELS

Abstract: In this research, the oxidation behaviour of high Aluminum heat resistant steel (%۲۵Cr,%۲۰Ni,%۸Al) hasbeen evaluated at the temperature range of (۱۰۰۰-۱۳۰۰ºC).The results showed that there was no countinous healinglayer on the surface of the alloy when Al increased up to %۵.۵ and the oxidation resistance of steel decreased due toformation of spinel oxides on the surface.By increasing the aluminum amount to %۸, only Al oxide formed due to decreasing carbon potential of thealloy,homogenity of elemental concentration in matrix and no diffusion of  oxygen through oxide–metalinterface,therefore it has superior oxidation resistance. Meanwhile,oxidation tests showed that the weight gain of thesteel at high temperature oxidation even at ۱۳۰۰ºC was too low.

Keywords:

Keyword : High Aluminum steel , Heat resistant steel , Oxidation resistance , Protective -Al۲O۳.