Development of a hot tear indicator for steel castings

A hot tear indicator based on the physics of solidification and deformation is presented. This indicator is derived using available data from computer simulation of solidification and solid deformation. Hot tears form when the mushy zone is starved of liquid feeding and deformed in tension. The unfed tensile deformation causes a small additional porosity. A physical model based on a mass balance is developed to find the additional porosity formed. This additional porosity or porosity due to solid deformation (PSD) is a locator for initiation sites for hot tears in the casting, not a full tear predictor. Simulation results for various “T”-shaped steel castings show good agreement with previous experimental findings. Reducing the strain in the casting and increasing the feeding of the section are found to decrease the hot tear tendency.