Credibility of various plastometric methods in simulation of hot rolling of the steel round bar

Abstract

Rolling of round bar made of steel 32CrB4 was simulated physically. The interrupted torsion test led to the fi nal microstructure with coarser grains, however, thanks to comparatively large dimensions of the sample this type of experiment was not so sensitive to the cooling rate of the fi nal cooling as compression test. Too high temperature of the end of controlled cooling of the samples after compression test led to partial self-quenching of the investigated material. Decelerated cooling below the temperature of the start of martensitic transformation led in both applied types of compression tests to the parameters of the resulting microstructure and hardness closest to the parameters obtained after laboratory rolling.