Effects of Grain Refiner and Cooling Rate on Solidification Structure of H62 Brass

Abstract

In this paper, effects of different grain refiners on solidification structure of H62 brass under different cooling rates were investigate by macro corrosion, SEM and EDX analyses. Results of experiments indicate that the columnar crystal zone of H62 brass is completely eliminated and the grain size is reduced remarkably by 0.01%B. It has been found that the columnar grain zone is also eliminated by 0.1Ti, 0.1Zr, 0.1Ti+0.1Zr and 0.1Ti+0.1Zr+0.01B additions, respectively, but their grain refining effects are not as good as 0.01B. The grain size of H62 ingot with 0.1Ti addition prepared by sand mold casting is coarser than prepared by permanent mould casting. The microstructures of as cast H62 alloy are composed of α dendrite phases and rodlike β' phases which enrich on grain boundary to form an array structure.