Papers by Author: Lin Chen

Abstract: In this paper, based on electric quenching production process in rail and beam factory of Baotou steel, using the finite element software DEFORM-3D, with 60kg/m U75V rail as the prototype, established a three-dimensional model of rail residual heat quenching to simulate and calculate evolution law of tissues and stress on rail head in quenching cooling process in quenching unit, and provides a theoretical basis for finding reasonable optimal cooling rate of rail head in the rail online residual heat quenching process.

Abstract: In this paper, for the rail U75V rail head spray quenching process temperature field, we founded model, meshed, loaded, and solved the finite element simulation of the process by using ABAQUS finite element analysis software, and carried on the site test using the infrared thermal imager, we received the changing discipline with time of the temperature of rail. The results of simulation are close with actual process. The precise calculation for the future in the process of quenching heat stress and residual stress laid the foundation experiment.

Abstract: This paper analyzes the TTT and CCT curves of U75V as a research basis, detailed anatomical U75V chemical properties and grain structure, through thermal simulation machine, heating 820 °C, respectively, and 920 °C, respectively, the sample detection U75V 2 °C / s, 4 °C / s, 6 °C / s, 10 °C / s, 15 °C / s, 20 °C / s speeds cooled Rockwell hardness, and observing samples taken U75V phase diagram. Through data analysis and image contrast, pearlite lamellar microstructure observation, analysis hardness and lamellar spacing, summed pairs of different cooling rates U75V organizations and hardness.

Abstract: In this paper, the effect of rail head organization, cooling and quenching microstructure transformation time in different cooling speed are analyzed by the numerical simulation of the 60kg/m U75V, and study the change law of the rail temperature field and microstructure in the quenching process in the field.

Abstract: In order to guarantee organization and performance requirements of H-beam, a certain compression ratio is needed from stock to products. This paper choose blank special-shaped billet, using DEFORM finite element software, simulated and analyzed change rule of H-beam equivalent strain when beam blank is cogging. Simulation results show that:The compression ratio is 10.78 from stock to products. The stock dimension meet requirements of from A hole to CCS rolling after BD cogging. The equivalent strain rule during the entire process of beam blank cogging is mainly focus waist and haunch joint.

Abstract: 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.

Abstract: Of hot rolling 100-meter heavy rail, the shrinkage masses or swell increments are different in different positions of transverse sections during the cooling process by the reason of profiled cross-section, which resulted in alternating bend, and the flatness and residual stresses are directly affected by bending deformation before straightening during the cooling process. In this paper, By studying the heat boundary conditions in cooling process, the regularity of bending deformation of hot rolling heavy rail during cooling is observed, adopting 3-D transient nonlinear FEM simulation. By controlling the deformation value of bending before straightening and the value after straightening, the influence of residual stresses after straightening from pre-bending values before straightening is analyzed, drawing a conclusion of the regularity that residual stresses are affected by different chord heights at the same straightening rule, and the calculated results have a good accordance with the real values in field scene.

Abstract: Against the problem of roller surface nodular of Baotou sheet steel factory galvanized vertical reduction annealing furnace, products defects of dezincification, leak plating, scratches before galvanized and so on, and from these aspects of analysis including the vertical annealing furnace’s working principle and structural characteristics, it was found that these main reasons causing this fault was that entry seal roller did not turn for high temperature deformation and condensed water of roller surface pollute strip steel, by improving the design and transformation of entry seal structure, the defects which caused by these reasons is solved, greatly improved the quality of the products, and there for provide the safeguard for the continuous and stable operation galvanized units.

Abstract: This paper used the finite element software to simulate the process of the heavy rail rolling deformation between the UR and ER racks. It studied on the stress distribution law of the universal mill pass, the relationship between the universal mill unbalanced rates of velocity and tension changes of the rack, effect of the universal mill unbalanced rates of velocity on the change of the rolling geometric dimensions caused by the unbalanced rates of velocity. The research can guide the adjustment of the dimensional accuracy of the rail’s universal rolling.

Abstract: A solid model and finite element model of nine-roller constant roller spacing of large H-shaped steel were set up, researching the problems of elastic-plastic deformation in straightening simulation for nine rollers continuous straightening process of large H-shaped steel. Through analyzing the stress and strain relation of large H-shaped steel, and analyzing the residual stress of H-shaped steel in the straightening process, a theoretical basis for the further step analysis the residual stress control after the H-shaped steel straightening was established.