| Non-quenched and tempered steel bar is a typical automotive crankshaft steel, its mechanical properties can better meet the requirements of small and medium-sized steam power diesel engine and diesel machine. But because of the cooling process after rolling temperature field coupling, organization field, stress field changes, eventually there will be a large bar of residual stress. The bar after machining, the stress is released, some parts of the deformation cannot satisfy the requirements of the dimensional accuracy, so having the research about the process of the bar during cooling after rolling to reduce the residual stress of bar is very necessary.In this paper, with a diameter of 120 mm 42Cr Mo as the research object, according to the characteristics of non-quenched and tempered steel bar during cooling after rolling temperature and organizational change, considering the influence of nonlinear factors of boundary heat transfer coefficient, latent heat and thermal parameters etc. Creating a three-dimensional coupling analysis model established the stress field temperature field and microstructure transformation. The establishment of the corresponding finite element analysis model, studied change of the temperature field, phase transformation and stress field after rolling in the process, and make the tissue distribution, stress distribution was compared with the experimental results, obtained the final residual stress distributing state. Analyze the mechanism of residual stress in the process of cooling after rolling comprehensively and systematically.According to the related experimental data and mathematical model, using VB software development, write " non-quenched and tempered steel bar after rolling cooling temperature field, microstructure distribution, stress field numerical simulation software, optimization of non-quenched and tempered steel bar cooling after rolling process parameters, reducing the residual stress has a certain guiding significance. |
PDF Full Text Request