Numerical simulation study on solidification proceoss of titanium slab ingot by electron beam cold hearth melting

Abstract

Titanium and titanium alloys are key basic support materials in the field of engineering technology and high technology, and are widely used in the fields of natural gas transportation, chemical corrosion, and marine development. Titanium alloy ingots are often prepared with more solidification defects such as surface cracks and cold shuts, resulting in lower utilization of titanium metal and higher cost of titanium products. The root of this is the lack of in-depth knowledge of the ingot melting and casting process, and the failure to control the thermal conditions of the billet in the molding process within a reasonable range. In this study, based on the Lagrange Euler algorithm, combined with ProCAST finite element software to establish a numerical model, revealing the solid–liquid interface morphology, the length of the transition region, and the change rule of thermal stress under the influence of different process parameters in the solidification process of titanium slab ingot. The results show that with the increase in pulling speed, the depth of the solid–liquid phase line and the width of the mushy zone of slab ingot increase, and the length of the transition region grows. With the increase in casting temperature, the depth of the solid–liquid phase line of the slab ingot decreases, and the mushy zone gradually becomes narrower. The casting temperature and pulling speed are positively correlated with the value of the thermal stress equivalent stress in slab ingots, and the probability of cracks in the corners and ingot surface is higher. This study provides effective theoretical guidance for the realization of stable mass production of high-quality titanium slab ingot.