| he effects of austenite grain size, level of undercooling, and strain and strain rate in compression on the austenite-to-ferrite transformation in a 0.1% C, 1.4% Mn steel were investigated. The influence of this transformation on the hot ductility of the steel in question was then examined. Samples were strained at rates from ;Deformation was found to raise the effective Ar;In tension, it was found that, if thin bands of grain boundary ferrite were present in the microstructure, failure always occurred in this second phase. The effect of intergranular ferrite on the ductility was found to vary with the amount present; the lowest %RA value was obtained with around 10% ferrite present in the microstructure. The detrimental effect of ferrite lessened slightly as the strain rate was raised.;It is concluded that, from an industrial perspective, unless unbending can be performed at strain rates in excess of... |
