Room Temperature

Ferritic steels have relatively low yield strength and the work hardening of these steels is limited. Their strength increases with increasing carbon content, but the effect of chromium on strength is negligible. However, ductility is lower in steels with high chromium content and for optimum ductility, the levels of carbon and nitrogen must be kept to a minimum.

Elevated Temperatures

Ferritic steels have relatively high strength up to 500 °C. The creep strength, which is usually the determining factor at temperatures above 500 °C, is low. The normal upper service temperature limit is set by the risk of embrittlement at temperatures above 350 °C. However, due to the good resistance of chromium steels to high temperature sulphidation and oxidation, a few high chromium-alloyed grades are used at higher temperatures.