The bainitic and martensitic transformation of iron-chromium-carbon and iron-silicon-carbon alloys

摘要

To obtain a better understanding of the austenite-martensite and austenite-bainite transformation, a metallographic study added with dilatometric measurements has been made. The mainly used tool steel 100Cr6 representing the system Fe-Cr-C and the austempered ductile cast SCI 1000 ADI representing the system Fe-C-Si and of engineering interest have been used as master material. The transformation characteristics depend upon the chemical composition and the homogeneity of the alloy, but also upon suitable heat treatment parameters. The morphology and microstructure after austenite-martensite and austenite-bainite transformation have been investigated and proved by transmission (TEM)- and scanning (SFM)-electron microscopy. Structural characteristics due to the thermal treatment and changes caused by alloying elements of both systems are discussed.