Effect of sand blasting on oxidation behavior of K38G superalloy at 1000 °C

• Pre-sand blasting changes oxidation behavior of superalloy K38G.
• Pre-sand blasting influences little on the oxidation kinetics.
• Pre-sand blasting changes the oxidation growing mode.
• Pre-sand blasting suppresses the diffusion induced recrystallization process.

The impact mechanism of sand blasting on oxidation resistance of K38G superalloys was investigated. Results show that sand blasting influenced little on the oxidation kinetics but suppressed the DIR (diffusion induced recrystallization) process, i.e. keep the original crystal orientation of substrate. Besides, sand blasting refined the crystal size and changed the growing mode of oxide scales by changing the diffusion mechanism, being reflected in the variation in surface morphologies of scales from a feature of piles plus valleys for the polished ones to a feature of flat surface appearance with micrograins for the sand blasted alloys.