Influence of alloying elements on the thermal contraction of peritectic steels during initial solidification

A modified SSCT (submerged split chill tensile) test was used to measure the contraction forces occurring during the solidification of steels with a carbon content of between 0.05 and 0.2 wt-% at constant Mn (1.55%) and Si (0.3%) contents. Further test series were performed with varying Si, V, Cr, Mn, Ni and Nb contents at a constant C content of 0.1%. Any cracks generated were detected, counted and measured. The total crack length allows conclusions to be drawn about the influence of alloying elements on crack susceptibility. The measured results match very well with results calculated from hot tearing criteria. Besides the steel composition, the superheat of the melt proved to be the most important factor in crack formation caused by contraction.