| Title |
Microstructure of Plain Carbon Steels Irradiated by Accelerated Electron Beam |
| Authors |
서동우(Dong Woo Suh); 이성학(Sung Hak Lee); 구랑모(Yangmo Koo); 권동일(Dongil Kwon); 김방광(Bankwang Kim) |
| Abstract |
The present study is concerned with the microstructural analyses of the surface layer hardened by the irradiation of accelerated electron beam in 0.2% and 0.4%C plain carbon steels. Steel specimens were irradiated using an 1.4 MeV electron accelerator, and the microstructures of the irradiated surface regions were examined. Upon irradiation, the ferrite-pearlite matrix adjacent to the specimen surface was changed to the ferrite-martensite structure, whose interface was composed of fine particles and needle-like lamellae. In order to investigate the martensitic transformation mechanism, the simulation test including thermal cycles of abrupt heating and quenching was carried out. It was found from this test that the temperature of the irradiated surface layer was raised to about 1100℃, which was enough to obtain the surface hardening through the transformation from pearlite to martensite. It is also suggested that the proper accelerated electron beam conditions such as the carbon content and the heat input should be determined to improve microstructures for the surface hardening. |