The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies, namely iron mould casting and continuous casting. The results revealed that t...The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies, namely iron mould casting and continuous casting. The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks, which were greatly refined in the ingot made by continuous casting process, compared with that by the iron mould casting process. M2C eutectic carbides presented variation in their morphologies and growth characteristics in the ingots by both casting methods. In the ingot by iron mould casting, they have a plate-like morphology and grow anisotropically. However, in the ingot made by continuous casting, the carbides evolved into the fiber-like shape that exhibited little characteristics of anisotropic growth. It was noticed that the fiber-like M2C was much easier to decompose and spheroidize after heated, as a result, the carbides refined remarkably, compared with the case of plate-like carbides in the iron mould casting ingot.展开更多
As one of the basic finishing operations,loose abrasive lapping is widely used in the surface finishing on metallic parts,non-metallic components,and engineering ceramics.During lapping,lapping parameters have a great...As one of the basic finishing operations,loose abrasive lapping is widely used in the surface finishing on metallic parts,non-metallic components,and engineering ceramics.During lapping,lapping parameters have a great influence on surface quality of machined workpiece.In order to provide an experimental basis for the selection of lapping parameters,effects of some important variables such as abrasive size,lapping load,and lapping speed,on surface roughness and residual surface stress of high speed steel workpiece via loose abrasive lapping were discussed in this paper.The results show that the work surface roughness increases with the increasing of abrasives size or decreasing lapping load,and does not change obviously with the lapping speed.Lapping can cause residual compressive stress in the surface layer of lapped workpiece,and the magnitude of residual surface stress becomes larger with increasing abrasive size,lapping load,and lapping speed.展开更多
基金supported by the Fund Project for Transformation of Scientific and Technological Achievements of Jiangsu Province,China(No.BA2010139)
文摘The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies, namely iron mould casting and continuous casting. The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks, which were greatly refined in the ingot made by continuous casting process, compared with that by the iron mould casting process. M2C eutectic carbides presented variation in their morphologies and growth characteristics in the ingots by both casting methods. In the ingot by iron mould casting, they have a plate-like morphology and grow anisotropically. However, in the ingot made by continuous casting, the carbides evolved into the fiber-like shape that exhibited little characteristics of anisotropic growth. It was noticed that the fiber-like M2C was much easier to decompose and spheroidize after heated, as a result, the carbides refined remarkably, compared with the case of plate-like carbides in the iron mould casting ingot.
文摘As one of the basic finishing operations,loose abrasive lapping is widely used in the surface finishing on metallic parts,non-metallic components,and engineering ceramics.During lapping,lapping parameters have a great influence on surface quality of machined workpiece.In order to provide an experimental basis for the selection of lapping parameters,effects of some important variables such as abrasive size,lapping load,and lapping speed,on surface roughness and residual surface stress of high speed steel workpiece via loose abrasive lapping were discussed in this paper.The results show that the work surface roughness increases with the increasing of abrasives size or decreasing lapping load,and does not change obviously with the lapping speed.Lapping can cause residual compressive stress in the surface layer of lapped workpiece,and the magnitude of residual surface stress becomes larger with increasing abrasive size,lapping load,and lapping speed.
