Effects of Alloying Additions on Thermal Conductivity of Ferritic Iron

Thermal conductivity is one of the most important properties for iron-base heat-resisting alloys. For the alloys with low thermal conductivity, the temperature is not readily homogenized over long distances and thus the alloys will be locally heated. Such local heating may cause degradation of the heat resistance owing to local melting, local oxidation, etc. Thus, in order to avoid the degradation due to the local heating, high thermal conductivity is indispensable for the heat-resisting alloys. Alloying elements usually improve the mechanical and chemical properties of iron, but may degrade the thermal conductivity. Consequently, information on the thermal conductivity is needed for determination of the alloying elements and their concentrations of the alloys. Unfortunately, however, such information is very limited even in binary Fe-X systems so far. In the present study, the thermal conductivity has been experimentally determined for various iron-base binary alloys.