ABSTRACT
In this section, the phenomena of static and metadynamic recrystallization are described together, since these two softening mechanisms (SRX and MDRX) take place during interpass time. When the steel experiences the transition of the hot-restoration mechanism at the critical strain ec, the microstructure will be significantly affected by the softening mechanism. However, it is difficult to find the dependence of the softening mechanism on strain at єс. Thus we usually investigate the occurrence of MDRX at peak strain ερ, where the dynamic recrystallization was already initiated. It must be noted that the critical strain is located in the ranges of 0.5ερ to ερ. SRX and MDRX studies are carried out by inter rupting torsion tests by changing the strain given on the specimen, such as 0.25ερ, 0.5ερ, ερ, and 2ερ. The fractional softening is related to the SRX if the strain was selected as 0.25ερ and 0.5ερ, which are smaller than the critical strain ec. If a strain larger than critical strain were selected, the new grains would be dynamically nucleated without incuba tion time and then statically grown, implying an MDRX.
