| Title |
Kinetics of Chromium Diffusion Coating onto Pure Iron and Carbon Steel in Molton Lead Bath |
| Authors |
유근걸(Kun Kul Yoo); 이재영(Jai Young Lee); 김종희(Chong Hee Kim) |
| Abstract |
Kinetics associated with the formation of chromium diffusion coated layer and chromium carbide onto pure irons and carbon steels in molten lead was studied. Chromium diffusion process was carried out by dipping the specimen in molten lead bath containing dissolved chromium at various temperature and time. The effect of dipping time, bath temperature, and carbon content in the specimen on the diffusion process was described. The result indicated that for the pure iron, the rate controlling step was the chromium diffusion into the metal and the relationship between the diffusivity of chromium, D_a and absolute temperature T was D_a=(1.505) exp[-52.8±7.7(㎉/mole)/RT] The concentration of chromium in surface layer was increased almost linearly with carbon content in the specimen. The result also showed that the hardness of diffusion coated surface in carbon steal was greatly increased due to the formation of carbide. |