Microstructure and corrosion characteristics with annealing of Zr-based alloys

摘要

The effects of final annealing temperature onmicrostructure and corrosion behavior of Zr-based alloys wereinvestigated. Four kinds of Zr alloys were used for microstructuralstudy and corrosion test. Corrosion tests were carried out in staticmini autoclave under 400 deg C steam condition. Microstructureswere analyzed by using TEMIEDS and image analyzer. The grainsize and precipitate size of Zircaloy-4 increased with increasing theannealing temperature. As the annealing temperature increased, thecorrosion resistance of Zircaloy-4 also increased due to theincrease of precipitate size and grain size. Therefore, theprecipitate size and grain size play an important role on the controlof corrosion resistance of Zircaloy-4. However, it was consideredfrom this study that the corrosion resistance of Nb-containingalloys would be controlled by the characteristics of beta phaserather than precipitate size.