Strain-induced precipitation was observed in Nb + Ti dual stabilisation 17%Cr ferritic stainless steels. Nb-containing precipitates were observed in the case of 0.4%Nb but not in the case of 0.2%Nb addition. The precipitation induced by strain is identified (Nb,Ti)C, which is a NbC-rich structure and different from the precipitation in undeformed specimens. The (Nb,Ti)CNbC-rich particles occupied Nb atoms and prevented Fe2Nb from precipitating. The precipitation transformation in 17Cr-0.4Nb-0.2Ti steel is shown as below:
The pinning effect induced by (Nb,Ti)C makes stainless steels difficult to hot roll, which is in agreement with actual production.
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