2013 年 54 巻 625 号 p. 163-169
Bainitic TRIP (transformation induced plasticity) -type hot-rolled strips with a tensile strength of 980 MPa were manufactured with an actual tandem hot strip mill. The importance of ultra high strength steel strips has been increasing with the weight reduction of automobiles. TRIP-type steel strips have both high strength and excellent workability for forming final products. Despite the popularity of continuous annealing for producing ultra high strength bainitic TRIP-type steel strips, few studies have been conducted with respect to the production of bainitic TRIP-type hot-rolled strips. The retarding effect of chromium on bainitic transformation was confirmed by experiments at low cooling rates using a laboratory mill and a salt bath, which simulated coiling after hot rolling.