Abstract
Silchrome steel is a heat-resisting steel, containing Cr and Si as main alloying elements, and widely used for exhaust valves in the automotive field.
But there are many difficulties in manufacturing this kind of steel: for example, the quenching effect is insufficient, the distribution of carbide is irregular, the fracture is very coarse and the impact value is lower.
After several considerations on the causes, the authors assumed that the troubles were caused an account of the improper chemical composition. From investigation of the sectional diagram of Fe-C-Cr-Si series, the author proved that their assumption is right; according to the present diagram, it may be successfully shown that the phenomena mentioned above happen when the chemical composition lies in the gamma-loop region.
