Quantitative Evaluation of Thermally Induced Residual Stresses in White Cast Iron and Steels with Different Cementite Morphologies
The starting point for this work were damages in rolls of chill casting. Results of damage analysis have shown that the reason for these damages were cracks caused by thermally induced residual stresses. The reason for these microstructural residual stresses is a mismatch in the thermal expansion coefficients between the ferrite and cementite phases. It is well known that the termal expansion coefficients of the ferrite and cementite phases are identical approaching the Curie-temperature of cementite (TC=210øC for pure Fe3C), whereas they are quite different at room temperature. Below the Curie-temperture the thermal expansion of cementite is smaller than that of the ferrite phase.