Study of phase transformations within bimetallic rolling mills

With the aim of simulating the cooling behavior after a re-austenitizing stage of bimetallic rolling mills, both materials corresponding to spheroidal graphite iron (core material) and high chrome steel (shell material) must be characterized through thermo physical and mechanical tests as well as microscopic observations. Dilatometer tests were carried out for both materials in order to determinate thermo physical properties such as thermal expansion coefficient and density. Compression tests were also performed in order to estimate the effect of mechanical stress on martensite phase transformation, especially the nature and the type of martensite and start of transformation temperature.
However there are some parameters that are still unknown and that are highly difficult to determinate. Inverse simulations are performed through Lagamine code with the aim of finding an estimated value for these parameters or improved parameters, more accurate than the ones already estimated.