Influence of aging at hot bands on recrystallization temperature of cold rolled sheets in Nb-bearing ferritic stainless steel

The influence of aging at hot bands on the recrystallization of cold rolled sheets in a 15 mass%Cr-0.46mass%Nb ferritic stainless steel was investigated. The results obtained are as follows: (1) The recrystallization temperature of cold rolled sheets which were aged at the temperature range from 700 degrees C to 750 degrees C for 2 hours or long times in hot bands was lower than that of no aging. After aging of hot bands, the content of Nb as precipitates was about 0.45%, which was nearly equal to the total content of Nb. The main precipitates was detected as Fe2Nb-Laves phase. It is considered that Fe2Nb-Laves phase, which grows coarsely during hot band aging, is contributed to lowering the recrystallization temperature of cold rolled sheets. (2) In the case of no aging in hot bands, a large amount of solute Nb existed in hot bands before cold rolling. Fine Fe2Nb-Laves phase precipitating at approximately 700 degrees C might mainly suppress the recrystallization of cold-rolled sheets.