1987 Volume 73 Issue 9 Pages 1146-1153
The recrystallization behavior of austenitic stainless steel in high speed hot rolling has been investigated in relation to the strain distribution through the thickness of the rolled strip. The strip of which the size was 2.1 × 20 × 760 mm was rolled at the temperatures from 900°C to 1100°C and at the mean compressive strain rate of 600 s-1 with or without lubrication. The rolled specimen was quenched in water at the interval of 60 ms after rolling. The redundant shear strain caused by friction forms severely sheared region beneath the surface with the thickness of about 100 μm. The maximum equivalent strain εmax in rolling without lubrication is always larger than that in lubricated rolling.
A band of extremely fine recrystallized grains (d= 27 μm) are formed in severely sheared region when εmax exceeds the critical value, which is dependent on Zener-Hollomon parameter Z0 at the mid-thickness of the strip and independent of lubrication condition. The size of the recrystallized grains is strongly dependent on Z0 and independent of εmax. It cannot be made clear from this experiment whether this recrystallization occurs dynamically or statically. It seems, however, that dynamic recrystallization possibly takes place because the recrystallized grains appear even in the strip quenched after a short holding time of 3.5 ms.
