摘要：This work presents a simplified model to predict strain and stresses produced during heat treatment of ferrous alloys, using the finite element method. From a computational point of view, this problem requires coupled thermal-metallurgicalmechanical analysis, modeled as non-stationary and nonlinear processes. Calculation of metallurgical properties is coupled directly with thermal analysis, because thermal properties depend on microstructural composition. Metallurgical transformations occurring during the process are important in the development of internal stresses and distortions, because they change mechanical properties of the metal, but also involve specific volume changes that are coupled to thermal dilatations. The microstructures formed during heat treatment depend on alloy composition, temperatures and cooling rate, as can be observed in TTT or CCT diagrams. For a given material, their properties could be considered as functions of temperature and microstructural composition and, in a second analysis, as functions of temperature and time. Taking into account the difficulties to obtain material parameters to model accurately their properties with more sophisticated models, a piecewise linear model is proposed. A numerical example applied to a real case is presented.
其他摘要：This work presents a simplified model to predict strain and stresses produced during heat treatment of ferrous alloys, using the finite element method. From a computational point of view, this problem requires coupled thermal-metallurgicalmechanical analysis, modeled as non-stationary and nonlinear processes. Calculation of metallurgical properties is coupled directly with thermal analysis, because thermal properties depend on microstructural composition. Metallurgical transformations occurring during the process are important in the development of internal stresses and distortions, because they change mechanical properties of the metal, but also involve specific volume changes that are coupled to thermal dilatations. The microstructures formed during heat treatment depend on alloy composition, temperatures and cooling rate, as can be observed in TTT or CCT diagrams. For a given material, their properties could be considered as functions of temperature and microstructural composition and, in a second analysis, as functions of temperature and time. Taking into account the difficulties to obtain material parameters to model accurately their properties with more sophisticated models, a piecewise linear model is proposed. A numerical example applied to a real case is presented.
