Effect of annular seams on stress-strain state in cylindrical ceramic shell mold during solidification of a steel casting in it

During the crystallization of liquid metal in a shell casting mold, significant normal stresses occur on its surfaces. On the inner – compressive, on the outer – tensile. They are especially pronounced at the initial moment of cooling time. This can lead to damage to the casting mold, and hence damage to the crystallizing metal casting. It is possible to reduce the level of stress-strain state in the surface layers by applying special annular (temperature) recesses (seams) to the outer and inner surfaces. In this paper, the problem of the influence of temperature seams in inner and outer layers of a shell mold (SM) on the level of its stress-strain state (SSS) during crystallization of a steel casting was formulated and solved. The normal stresses σ 22  , σ 33  , which occur both on the inner and outer surfaces of SM at the initial moment of metal casting and cooling of the steel casting, are accepted as a parameter of SM resistance to cracking. An axisymmetric problem for a cylindrical ceramic SM is considered. Based on the formulated objective function, the paper presents an algorithm for solving the problem using the equations of the linear theory of elasticity, the equation of thermal conductivity and the proven numerical method. As a result of solving the problem, the minimum number and locations of recesses on the inner and outer surfaces of SM, ensuring a decrease in normal stresses, were determined. The results of solving the problem are presented in the form of stress plots across the sections of the considered area. The authors analyzed the obtained results of SM resistance to cracking and gave recommendations on the use of the obtained results in various scientific and technical fields.