H-beam Rolling Research Articles

Mechanics of the H-Beam Rolling in the Universal Beam Groove

The formulation and solution of the problem of double-T section rolling in universal groove using the variational principle of minimum total power with aim to determine integral forming and energy-power parameters are presented. Geometrical model of the deformation zone and the kinematically admissible velocity field were constructed accurate within two unknowns: forward slip coefficient ν, flange spread (pulling-down) . The comparison of the calculated values with the experimental data obtained on a laboratory mill 200 confirmed that the variational principle of minimum total power has sufficient accuracy for analysis of double-T section rolling in universal groove. The mean statistical error of torque calculation is 12.3 % while load calculation is 18.7 %.

Determination of Contact Pressure during Double-T Section Rolling in Universal Beam Groove

Based on application the physical constraint equations of state of stress and strain of the metal for the isotropic medium, we get expressions for components of stress tensor. The new theoretical method for calculation of contact pressures and rolling force during rolling of double-T section in a universal beam groove was developed. Reliability of the method is confirmed by the results of experimental verification for conditions of rolling of H-beam No 35B1, 40K2 and 45B2 from steel 15CrSiNiCu on the universal beam mill of "NTMK". The average calculation error is 6.4%. The new method is recommended for calculation pass design and technological modes of H-beam rolling on rail-beam and section mills, equipped with universal stands.

Development of simulation system for large H-beam hot rolling based on ABAQUS

H-beam is a kind of efficient economic cross-section steel with wide flange and thin web. Due to the superior cross-section properties and reasonable strength-to-weight ratio benefiting from its especial shape, H-beam has been widely used in the industry and building trade. However, since the hot rolling of large H-beam is a highly nonlinear plastic deformation process which happens under the high temperature and high pressure, the real-time detection of internal information for H-beam and deformable roller in the rolling process is difficult to be realized. The finite element simulation is an effective measure to demonstrate the internal information during the whole hot rolling process. However, the drastic plastic deformation involved in the transient rolling process may lead to meshing distortion in simulation which would result into inaccurate simulation results. In this paper, the finite element simulation system for large H-beam hot rolling is developed based on ABAQUS and thermal coupled elastic-plastic finite element method by customizing applications and embedding re-meshing algorithm and subroutines. Modeling of pre-processing and extracting simulation results of post-processing can be automatically achieved through the simulation system. The re-meshing algorithm and the information transfer method of the clearance between two passes are synthetically used to ensure the continuous simulation of multi-pass hot rolling process and improve the accuracy of simulation results. The validity of the simulation system developed in this paper is verified through measuring the temperature field in hot rolling process of HN900x300 using a thermal infrared imager. The results show that the simulation results of the system are coincident with the measured results with errors below 6 %.

THE INFLUENCE OF GEOMETRICAL PARAMETERS ON INCREMENT OF H-BEAM FLANGES IN UNIVERSAL BEAM GROOVE

The mathematical model of metal forming under rolling of H-beam in universal beam groove was developed that enables to assess effect of the geometrical parameters on increment or pulling-down of a rolling section flange. The influence of draft ratio of web and flange on increment or pulling-down of flange and relative height of flange was determined.

Study on Metal Flow in the Finish Rolling Process of Large-Sized H-Beam

According to the production data of a rolling H-beam factory, the FE model of hot continuous rolling process of H-beam is built. With the FEM software of DEFORM-3D, the continuous rolling of H-beam was simulated. On base of simulation result, the metal flow and deformation law are discussed. Because of the flange and web is deformed in the different deformation zone, the metal flow law of flange and web is complex, especially the metal of the conjunction of flange and web. In this paper, the metal flow of large-sized H-beam in finishing rolling process is analyzed.

The Influence of Rolling Parameters on Metal Flow Law of H-Beam

According to the production data of a rolling H-beam factory, the FE model of hot continuous rolling process of H-beam is built. With the FEM software of DEFORM-3D, the continuous rolling of H-beam was simulated. On base of simulation result, the metal flow and deformation law are discussed. Because of the flange and web is deformed in the different deformation zone, the metal flow law of flange and web is complex, especially the metal of the conjunction of flange and web. The exchange of metal between the flange and the web of H-beam alters to the different elongation ratio of flange and web. The other factors which influents on the metal flow , are taken into consideration, such as rolling speed and friction coefficient. By adjustment to the rolling parameters, the defect of the H-beam is reduced.

빔 블랑크를 이용한 H 형강 압연 거동 연구

Metal flow of the beam blank during H-beam rolling was examined in order to correlate the rolling defects with the beam blank configuration. For this purpose, H-beam rolling was performed on the beam blank where stainless steel bolts were inserted as the marker at the web and flange. The positional variation of the marker was monitored at each rolling pass, and the result was compared with the 3D FEM simulation employing the point tracking function. The simulation results were reasonably agreed with the experimental within the error of 0.5~1mm on both web and flange of the H-beam. It is anticipated that the 3D FEM simulation employing the point tracking function provides the guidance information on analyzing the correlation between the rolling defects and the beam blank configuration in H-beam rolling.

Numerical Simulation Analysis of H-Beam Steel Controlled Cooling

The finite element analysis software soft ANSYS is used for researching H-beam hot rolling finite element model, temperature field and stress strain field. Then find the changes law in different water cooling conditions of the temperature field temperature distribution and the stress strain field. Find the heat coefficient of H-beam by using the optimization analysis to reduce the differences of the temperature and the stress strain value, and also reduce the deformation in H-beam cooling process. The controlled cooling parameters of H-beam under optimal conditions are determined by the simulation experiment and comparative analysis. While exploring the changes of H-beam microstructure, stress and hardness can provide the reference for the making and designing of reasonable controlled cooling technology.

Simulation and Technology Optimization for Rolling Web Wave of Large Size H-Beam

The rolling process of large size H-Beam NH800×300 in multiple working conditions was simulated by using of commercial finite element method software LS-DYNA. the web wave emerged during rolling of H-Beam was specially demonstrated. The main factor which affected the rolling force during the rolling process has been illustrated. The rolling process under the condition of different horizontal roller radius, different friction coefficient and flange/web stretching ratio were numerically simulated. By means of simulation with different flange/web stretching ratio, it could be concluded that the crucial situation to generate the rolling web wave in typical rolling pass is that the flange/web stretching ratio is about lower than 0.93, which may cause the web unstable and the rolling wave.

The Stress Laws of H-Beam Rolling Deformation during Rectangular Billet Cogging-Down

In order to ensure H-beam’s organization and performance requirements, there is a certain compression ratio from the rolling of the billet to the finished product. This paper select rectangular billets and use DEFORM finite element software to simulate and analyze the rules of stress variation when rectangular billet is cogged down. The simulation results show that: from rectangular billet to finished product, the compression ratio is 17.4 and after cogging, billet size meet the requirements of the CCS rolling. The equivalent stress of breakdown rolling is mainly concentrated in the waist or in the junction of waist and legs. In the first few pass，equivalent stress is mainly concentrated in Sharp-angled position of both top and bottom, however the next few pass’s equivalent stress is mainly concentrated in the junction of web Plate and flange.

The Stress Change Simulation Analysis for Beam Blank Cogging during H-Beam Rolling

In order to guarantee the requirements of H-beam microstructure and property, its must have a certain compression ratio in the rolling process from blank to finished products. This paper simulated and analyzed the law of H-beam equivalent stress change for beam blank cogging with software DEFORM. Simulation results show that the compression ratio is 10.78 in the rolling process from blank to finished products; after BD cogging, blank size meet the requirements of A hole by rolling one pass into CCS rolling, the law of H-beam equivalent stress mainly focus on the waist and haunch joint in the whole process of beam blank cogging.

Numerical Analysis of Multi-Pass H-Beam Hot Rolling Processing

Hot rolling is a basic metal forming technique that is used to transform preformed shape into final products of forms more suitable for further processing. As the hot stock progresses through the forming surfaces, the shape eventually reaches a constant state. With the assumption of forming process has reached steady-state condition, a simulation technique based on elements re-meshes has been constructed to analyze the H-beam metal hot roll process. The technique includes the following approaches: the solution was halted as soon as the steady-state criteria were met, and the plane of elements, which first satisfied the steady-state criteria were written to database, SSES for short; a two-dimensional model was created to model the hot stock cooling between the two roll passes and a geometric part was generated and meshed with quadrilateral elements to transfer the nodes temperatures; a new three-dimensional model extruded from the two-dimensional model was constructed to model the next roll pass with the transfer of nodes temperatures and element integration points equivalent plastic strain(PEEQ), identifying the plastic deformation extent for the classical metal plasticity models, from the new two-dimensional model and the first three-dimensional model respectively. Gleeble-1500 tester is used to get the true stress and true plastic strain data for modeling the yield behavior of material Q235. The effectiveness of the simulation technique has been proved by a simulation of 11-pass H-beam rolling process.

FEM Analysis of Large H-Beam in Rough Rolling Process

The Standard and Explicit solver of ABAQUS were synthetically used to establish finite element model for reciprocating multi-pass rough rolling of large H-beam, in which the re-meshing technique was utilized to solve the problem of excessive deformation and rollers’ deformation were taken into simulation to increase the accuracy. Based on the simulation results, stress field, thermal field and deformation behavior of the workpiece were discussed. It clearly showed that the main deformation of profiled blank in rough rolling was web broadening. Compare the analytical rolling force results to the practical rolling process, and this method could provide some valuable references to the rolling practice.

Control on Head Displacement of H-Beam in Rolling Process

The uneven elongation between flange and web can make long tongue in the head of H-beam, which can lead to too long crop end length. In order to control the tongue length of H-beam head, different elongation ratio between flange and web is put forward to control the head displacement of H-beam. If the flange and web elongation is uniform, the loss of crop end length will be reduced. At the same time, different cooling speed of flange and web is set to keep the section uniform temperature. Experimental investigations of H-beam rolling are carried out on the universal mill in the Rolling Lab of Hebei polytechnic University. Comparisons between experimental value and simulation results prove the correctness of elongation ratio of flange and web.

FEM Simulation of Multipass Shape Rolling Processes

The updating geometric method was proposed to simulate the deformation behavior of workpiece during multipass shape rolling by using finite element method. Firstly, establish and solve the finite element model of the first pass shape rolling process, then update the geometric shape of workpiece after the first pass and delete rolls of the first pass, establish and mesh rolls of the second pass, modify the boundaries and material parameters of workpiece, and solve its deformation behavior during the second pass shape rolling. With the same steps, its deformation behavior during the following passes rolling could be solved. The method was applied to simulate the deformation behavior of a cube workpiece during six-pass H-beam rolling with split-rolling, and its shapes after every pass rolling process were obtained. Experiments on the deformation behavior of slab during multipass rolling were carried out by using pure lead in an experimental mill. The calculated results are in good agreement with the experimental ones.

Distribution of Temperature Field for Rolling H-Beam

A 3D thermal-mechanical coupled was established for simulation model with technique of engineering thermodynamics and theory of nonlinear finite element during H-Beam rolling. The whole process of H-Beam rolling was repeated overall, and base on the known rolling regulations. The rules of temperature distribution were obtained for intersection deformation of web and flange during H-Beam hot rolling, and 45 steel as rolling stock. The studied achievements indicated that temperature of the stock presented tendency fall down, but tendency heighten in some domain, because of the thermal conductivity, heat radiation and convection and heat generation of plastic work done. The simulation results will have guiding meaning for defining rolling regulations and precise boundary condition of temperature for H-Beam.

3D Thermal Mechanical Coupled Elasto-Plastic Finite Element Analysis in the Whole Rolling Process of H-Beam

In the H-beam rolling process, the deformations and temperature field of workpiece significantly influence the mechanical properties due to the change of product microstructure. Prediction of them is important for the groove design and passes sequences. To get the deformation behavior and the temperature field of workpiece, commercial FEM program LS-DYNA has been used to analyze the whole process of H-beam rolling. The approach is based on 3D thermal mechanical coupled finite element method. The rolling process is divided into several units for calculation. The mesh of workpiece is rebuilt in the simulation for reducing the influence of element distortion. The result shows that, the temperature at the wed to flange position maintains the highest during the whole rolling process, while area of the web the lowest. After the rolling, temperature difference is above 150K between the web’s surface and flange’s inside surface, approximate 130K on the flange’s outside surface and 200K in the cross section. The simulation results show good agreement with the measured temperature data.

Three-dimensional finite element analysis of non-isothermal shape rolling

In shape rolling, prediction of deformations such as spread, elongation, and draft, pressure distribution between rolls and the workpiece, and forming load is important in designing proper roll grooves and pass sequences. Since initial temperature of the workpiece is in the range 1100–1200 °C, temperature distribution of the workpiece is a significant factor which influences the mechanical properties due to variation of microstructure in rolled products. Thus, variation of the workpiece temperature distribution during shape rolling should be considered at the design stage. In the present study, a three-dimensional finite element program for analyzing shape rolling processes considering heat transfer is developed based on rigid thermo-viscoplastic approach. Using the developed program, square–oval, round–oval, and square–diamond passes were simulated at different friction conditions with and without temperature effects. From the present simulation results, the non-isothermal and frictional effects on deformed shape, stress and temperature distributions of the workpiece, and forming loads were investigated. Also, in order to apply the developed program to more complex rolling problems, shape rolling of H-beam was simulated. The developed program will be useful in generating the database for designing roll pass and profile design in shape rolling.

Three-dimensional Numerical Analysis of Microstructural Evolution in and after Bar and Shape Rolling Processes.

An integrated numerical model predicting microstructural evolution, three-dimensional plastic deformation and temperature changes has been applied to industrial hot bar rolling and H-beam rolling. This model enables us to predict three-dimensional metal flow and temperature changes as well as transient in grain size change and dislocation density distribution in and after hot rolling. To demonstrate the successfulness of the proposed model, it was applied to the analysis of two different industrial bar rolling schedules, in which total number of passes and caliber systems were different with each other. It was also applied to the analysis of the H-beam rolling sequences with different heat treatment conditions. Microstructural evolution starting from deformed austenite to ferrite/pearlite/bainite after phase transformation was successfully simulated. Microstructural evolution in and after hot rolling as well as metal flow and temperature can be easily obtained through the proposed model using rolling condition and alloy composition as the functional variables. This model is a very useful tool for designing and optimizing rolling conditions so that products with the best internal quality and dimensional accuracy can be obtained.

Calculation of temperature and determination of deformation resistance in H-beam rolling: (2) Total change of temperature and deformation resistance

In this study, a formulation for shuttling temperature drop is developed, therefore the total temperature change in H-beam rolling can be determined, thus enabling the temperatures of the rolled piece before and after rolling at any pass in the continuous rolling process to be obtained. The deformation resistance of a material is a significant parameter influencing the rolling force and torque. The interpolation method is adopted to simulate the true experimental stress–strain curve. By this means the accuracy of calculation of the energy parameters has been greatly improved.