Study of hot tearing in stainless steel CF3M during casting using simulation and experimental method

Abstract

Hot cracking is a serious problem in casting of many alloys such as high-strength steels, austenitic stainless steels and aluminum alloys. In this study, the problem of hot tear during the casting of stainless steel CF3M (316L) cast in silica sand mold cored by CO2 was investigated. To do this, an in situ casting experiment using a T-shape mold equipped with K-type and B-type thermocouples, load cell, linear variable differential transformer and data acquisition system is used to characterize and quantify the hot tearing of CF3M during solidification along with simulation. Recorded thermal stress/force and displacement data are used for casting simulation and thermo-physical properties calculations. Simulation is carried out using casting simulation software, and thermo-physical properties were calculated using J-mat pro V8 software. Visco-plastic constitutive model was used to predict the hot tear; visco-plastic parameters play an important role to evaluate plastic strain. These parameters were derived from experimental and simulation data, and it is revealed that it is an accumulated plastic strain. Validation of developed model is part of future work. This study also focused on the effect of superheat on the hot tearing susceptibility of stainless steel alloy. Results have revealed that with increasing degree of superheat, the hot tearing susceptibility increases.