An experimental study was carried out to investigate the effect of acid etching on surface integrity of a single crystal nickelbased superalloy. The corrosion tests were conducted in solution of hydrochloric acid and hydrogen peroxide at different reactiontemperatures. The corroded specimens were characterized by scanning electron microscopy, weight loss measurements and surface roughness measuring instrument. The results indicate that DD6 suffers serious selective corrosion at cold bath temperature due to unduly slow etching when immersed for the maximum time. It is found that preferential dissolution of γ′ phase occurred, leading to the increase of surface roughness.
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