| Title |
Surface Hardening of Gray Cast Iron for Automotive Cylinder Block Using High-Energy Electron Beam Irradiation (1) ( Analysis of Microstructure and Wear Property ) |
| Authors |
추성훈(Seong Hun Choo) ; 이성학(Sung Hak Lee) ; 권순주(Soon Ju Kwon) ; 김상호(Sang Ho Kim) |
| Abstract |
The effects of high-energy electron beam irradiation on surface hardening and microstructural modification in a gray cast iron currently used for a diesel engine cylinder block were investigated in this study. The gray cast iron samples were irradiated by using an electron accelerator (1.4 MeV ), and then their microstructures, hardnesses, and wear properties were examined. Upon irradiation, the unirradiated microstructure containing flake graphites and the pearlite matrix was changed to martensite, ledeburite, and retained austenite, together the complete or partial decomposition of graphites. This microstructural modification improved greatly the surface hardness and wear property due to transformation of martensite whose amount and type were determined by the input energy density during irradiation. The peak hardness and the case depth were increased linearly with increasing the input energy density, and thus the high-energy electron beam irradiation can be effectively applied to the surface hardening process of a diesel engine cylinder block. |