电渣重熔连续定向凝固M2高速钢铸态组织的研究

摘要

研究了传统电渣重熔工艺(ESR)和电渣重熔连续定向凝固技术(ESR-CDS)所得到的M2高速钢铸态显微组织.结果表明:采用ESR工艺得到铸态组织边部为树枝晶且部分出现了三次枝晶,心部为粗大的等轴晶,晶粒之间有网状碳化物,铸锭的偏析较为严重,经深腐蚀凝固组织基体与碳化物过渡区较为疏松、粗糙,部分基体内部出现了细小的裂纹.而采用ESR-CDS工艺得到铸态组织边部和心部都以较为细小的树枝晶为主,组织中存在比较多的“不连续的复合规则型”的碳化物,组织较为均匀,经深腐蚀,碳化物与基体过渡区圆滑.%Abstract..The ESR and ESR-CDS casting microstructure of the M2 high speed steel was studied.The results show that the casting'edge is dendrite and appears three times dendrite with ESR,and the structure of heart are coarse equiaxed grains,between which is network carbide,and the segregation of ingot is more serious,the matrix and carbide transition region is loose and rough,and the fine crack is found of some part of the substrate with the deep etching.However,the structure of casting'edge and heart are small dentrite,and there are more "discontinuous composite regular type"carbide,the structure is more uniform,the transition zone of carbide and matrix is smooth with the depth of corrosion.