Heat flow distribution in electron beam rapidly quenched surfaces

Abstract

A theory of three dimensional heat flow, which has been used in metallurgical applications such as welding, is used to predict the heat flow distribution in electron beam rapidly quenched surfaces of metal. The results of the computerized heat flow analysis as applied to ultrahigh strength steel surfaces show that the cooling rates at points nearer to the surface are higher than those at greater depths. It is also shown that when the same traverse speed is used, the melt depth increases with increasing beam power. Theoretical results are compared with experimental results. Since the energy transfer efficiency from electron beams to metal surfaces is high, only low power electron beams are necessary to rapidly quench the metal surfaces. It is found that in the range of low power electron beams used in these experiments, the experimental results are in good agreement with the theoretical results.