摘要
The effect of external magnetic field on the solidification structure and impact toughness of high-speed steel(HSS)produced by electromagnetic centrifugal casting(EMCC)have been investigated.It was found that the solidification structure could be improved effectively by electromagnetic stirring,which was characterized by elimination of the inclined columnar dendrites and refinement of the grain size.The results may be related to the changes of the fluid layers of liquid-solid phase interface.Moreover,the impact toughness of the test steel increased with the exciting current increasing from 12 to 18 A,but decreased when the current was above 18 A.SEM analysis showed that impact fracture surface was dimple fracture due to effect of the refined equiaxed grains when the current was 18 A,which was considered an important reason for the improvement of impact toughness.
The effect of external magnetic field on the solidification structure and impact toughness of high-speed steel(HSS)produced by electromagnetic centrifugal casting(EMCC)have been investigated.It was found that the solidification structure could be improved effectively by electromagnetic stirring,which was characterized by elimination of the inclined columnar dendrites and refinement of the grain size.The results may be related to the changes of the fluid layers of liquid-solid phase interface.Moreover,the impact toughness of the test steel increased with the exciting current increasing from 12 to 18 A,but decreased when the current was above 18 A.SEM analysis showed that impact fracture surface was dimple fracture due to effect of the refined equiaxed grains when the current was 18 A,which was considered an important reason for the improvement of impact toughness.
基金
Item Sponsored by National Natural Science Foundation of China (No.51071136)
