Research On The Disciplinarian Of Inner Crack Healing In Plate Rolling Process

Currently, the work of experimental research and finite element simulation of the internal cracks healing under the hot rolling and deformation condition is seldom, so based on the related experimental research and the finite element simulation before, the thesis has a certain amount of improvement and innovation and conduct simulation and experimental study for healing discipline of internal cracks in rolled piece under the hot rolling deformation condition, for future research work related to provide certain experiment and simulation foundation, the main research contents and the results are as follows:(1) By using some improvement, producing internal preset crack in the size of φ5mm, through the experiment in thesis to research the evolution behavior of the plate internal crack in rolling process;(2) Through the experiment research in this thesis, the results are as follows:plastic deformation and diffusion and transference of atoms promote the healing of crack; along with the increase of the quantity of the pressure, the better the crack healing degree; when the total percent reduction is a constant value, the number of the rolling pass decrease, it means that each draught perpass increasing improved the crack healing degree; the closer the crack surface distance, the higher the degree of the crack healing; the higher the temperature at the beginning of the rolling, the better the crack healing;(3) Through the tensile experiments in this thesis, the results are as follows:along with the increase of the quantity of the pressure, tensile samples contained internal preset crack, and the yield strength and tensile strength of mechanics performance increase gradually; with the improvement of the temperature at the beginning of the rolling, tensile samples contained internal preset crack, and the tensile strength increase gradually, plastic improved; with the increase of percent reduction, in the fracture place of tensile samples contained internal preset crack, it’s more difficult to observe the trace of the top and bottom crack surfaces contact, and the size of the dimple fracture in the fracture place increase gradually, the number reduce gradually; with the improvement of the temperature at the beginning of the rolling, the size of the dimple fracture in the fracture place increase gradually, the number reduce gradually;(4) Through the ANSYS finite element simulation, in rolling process, the roll press direction stress of crack surface are negative, crack in that large pressure stress state, the state can restrict the development of the crack, be helpful for crack healing, at the same time, along with the increased amount of pressure, in the process of rolling crack surface roll press direction stress value increases, crack healing improves, and the simulation results fit the experimental results before perfectly.