Application of mathematical modelling to hardenability testing of low-alloyed Mn-Mo steel

In this work the hardenability, the degree of hardening, the cooling rates as well as the microstructures of low-alloyed Mn-Mo steel were investigated. In order to simulate the cooling process for the Jominy specimen a mathematical model based on finite element analysis was designed. For model verification the temperature was measured in real conditions. The Jominy curve for the steel showed that it was hardenable up to a depth of 22 mm. In the temperature range from 1133K to 973K cooling rates were calculated. They decreased from the quenched end producing the different microstructures (martensite, bainite) as a function of distance from the quenched end. The results obtained by modelling were confirmed by the data recorded in real conditions. A very good agreement with the measured temperatures was achieved with the given change of convective heat transfer coefficient on the quenched end face of the Jominy specimen.