| 摘要 |
Surface hardening of a cast iron component involving localised remelting is carried out under a protective gas shield by localised heating along melting tracks. Adjustment of the quantity of oxygen accumulated at the surface being hardened yields a desired surface density of the porosity of that surface, and the extent of overlapping of the melting tracks results in a desired pore fineness. Oil emulsion applied upon machining prevents oxygen absorption leading to low surface porosity. Conversely heating in the presence of air or oxygen leads to oxygen absorption and hence high surface porosity. <IMAGE> |
