Research On Austenite Microstructure Evolution In H-beam Hot Rolling

H-beam is a kind of multi-purpose, efficient and economical steel, its good performance owes to its excellent cross-section property. H-beam has high value in engineering. It will fill the growing role in the national economical construction. Studies indicated that refinement of H-beam can substantially increase mechanical properties without changing material. H-beam rolling process parameters have a major impact on the microstructure. The performance of H-beam products can be increased to meet the higher requirements by optimizing process parameters.In this paper, hot-rolled medium-sized H-beam was chose to be research topic. Thermal simulation experiment under high temperature between 800-1300℃was carried out by Gleeble-1500 thermal simulation testing machine, and obtained thermo-physical property of materials. The material property that mostly close to reality was provided to the computer simulation of rolling process.Three-dimension model coupled thermo-mechanical of FEM was built to analyze H-beam rolling process by large-scale finite element software ABAQUS. The initial condition and boundary condition etc were intercalated according to the actual working condition. Remeshing technique was used to carry out to multi-pass rolling of large deformation. FEM and BP methods were adopted to realize austenitic microstructure digital simulation, and the result is validated by temperature and metallographic observations experiments. Different combinations of the parameters were calculated, various parameters'impacts to the austenite evolution were found, and the factors of austenitic microstructure evolution were analyzed.Using thermal coupling large deformation theory, based on the analysis of deformation and temperature in hot rolling process, the production process parameters were optimized. The optimization results were predicted by finite element analysis, predictive results were better than the existing results.