Mechanical Analysis And Application Of New Technology Of Heavy Plank Forgeings-Making

Along with the rapid development of modern industry, such as energy, transportation and metallurgy, many heavy forgings with high quality are required. These forgings are made of ingots directly. Owing to both physical and chemical properties of metal material, there are inevitably shrinkage cavities, porosity and segregation in ingots. The larger the forgings size is, the more defects exist. Forging technology is needed to eliminate the defects to get high quality forgings. That is to say, with enough deformation, shrinkage cavities can be consolidated, porosity closed, segregation structure improved. To get this goal, there should be no tensile stress in the area where defects get together, or the situation be worsen. The old and new craftwork — stretching and broaching is a main deformation method for heavy forgings, and has great influence on forgings' quality. In this paper, this working procedure is simulated by using commercialized software ANSYS. Because of size character of board plank, In the process of stretching along B-direction, it is not satisfied with the blank width ratio and tool width ratio, which is required not forming pull-stress in the axis-direction and landscape orientation. So there is pull-stress in two directions in the area of transmogrification. When it is overturned 90 degree, the blank width ratio and tool width ratio is more than 1, then there is smart shear in the area of transmogrification. But in the analysis of broaching, the assumptions that it is plane strain, simulations of broaching are implemented. According to the numerical simulation and analysis, the relationship between the distribution of stress and strain in the symmetrical transmutative section and the reduction in height is researched, and the orderliness about the distribution of stress and strain is gained. It is educed that only when the reduction in height is litter there is pull-stress in the symmetrical transmutative section. Consequently, the mechanics model of broaching is perfected on rations. In the next place, the relationship between the distribution of stress and strain on the symmetrical transmutative section and the reduction in height is educed in the case of changing diameter of the bar and thickness of the roughcast. If the width (height) is taken into account, its effect on the stress and strain in the symmetrical transmutative section and its relationship with the reduction in height is investigated, which is three-dimensional stress and strain numerical simulation of broaching. Sequentially, the fit reduction in height is constituted, and it is proved that broaching avoids inapposite factors, which is blank width ratio and tool width ratio of stretching. At last, temperature influence upon the transmutative process is considered, so the thermal-structural couple field numerical simulation is done. The numerical simulation in this article gives the quantitative analysis. The transmutative state of broaching is gained by right of the preciseness of numerical analysis theory and the dependability of data. According to the new theory of stretching, forgings that doesn't accord with width ratio and tool width ratio can be formed transmutative state in the best ideal condition by special technologic instrument, which is avoids producing disfigurement. This task helps to perfect and develop the new theory of great forgings and new craftwork correlative—from experiential and qualitative analysis to quantitative analysis. That is the value and creativity of this paper.