Xiao Chen Wang

Research on High Pressure Abrasive Water Jet for Cold Rolling Descaling

This paper expatiated on principles of high pressure abrasive water jet descaling; used GAMBIT and some experience parameters to create the geometry model of the nozzles and the outflow field; used Fluent to simulate the high pressure abrasive water jet under the condition of different jet standoff distance, different impact angle, different mix angle, different abrasive particle size, different abrasive concentration and different abrasive material. Through the analysis of the simulation results, this paper put forward the optimal selection of these parameters.

On-Line Determination of Texture in Deep Drawing Steel Sheet by Two-Dimensional X-Ray Diffraction

This paper described the application of a diffraction system based on X-ray area detector on pole figure measurement as well as corresponding computation of orientation distribution functions and the principle of rapid measurement texture. The impact of calculates the orientation distribution function on the conditions of the two-dimensional X-ray diffraction was analyzed; this was illustrated by an example of deep drawing steel sheets texture measurement. ̙̈́˰͇̱̓˰̶̴̿̾ͅ˰̸̱̈́̈́˰̷̱̹͂̿̈́̈́̾˰̸̵̈́˰͇̈́̿˽̴̵̹̹̱̼̽̾̓̿̾˰̴̵̵̳̈́̈́̿͂˰̈́̿˰̸̵̈́˰̵̱̹̱̀̀͂̿̀͂̈́˰̂θ position then fix it, reduce the sample rotation; the texture determination time can be significantly reduced. Reduce the Measuring range of angle χ˰̴̱̾ φ˰̴̵̿̓˰̾̿̈́˰̶̶̵̱̳̈́˰̸̵̈́ calculation of orientation distribution function, it also can significantly reduce the measurement of diffraction data. Several technical problems appeared on the on-line determination of texture based on an X-ray two-dimensional detector system and the possibility to improve the measurement speed and accuracy in the industrial production applications were then discussed.

Research and Application on Spring Model of Hot Strip Mill

Spring model is important restrictive factors to improve the precision of AGC control system. To improve the accuracy of strip gauge control, Study on various influencing factors of spring model has important significance in rolling process. Therefore, using ABAQUS finite element software, this paper establishes the whole stand model of strip rolling. The model is used to analyze variation factors of the strip width and bending force to impact the longitudinal stiffness of rolling mill and get calculation model of the longitudinal stiffness of rolling mill. Then, this paper considers influence of the roller thermal expansion and wear factors influence on spring model and establish compensation model. The corrected spring model was applied to 1780mm hot strip mill in a factory in China, taking 45 strip head samples for measurement, with the model error under 50µm.

The Study of IOT Architecture for Steel Strip Production Process

Nowadays, IOT (Internet of Things) technology for the future intelligent manufacturing is still in its initial stage. In steel production, especially in steel strip production process, the research on how to construct IOT architecture is lack of research. This paper focused on the construction of IOT in steel Strip production process and analyzed the development of the industrial wireless sensor network standards. Based on the requirements of industrial networking monitoring in steel strip production process, this study proposed a feasible IOT network architecture for steel strip production process, which provided the basis for promoting further application of IOT technology in steel flat production process.

Analysis of Cold-Rolled Strip Profile in UCM Mill by Finite Element Method

In order to analyze the effect of entry strip thickness, entry strip crown and intermediate roll shifting on strip profile and rolling force distribution, a three dimension finite element model of rolls-strip in UCM mill was established and employed. The results showed that the increases of entry strip thickness and entry strip crown would lead to the increase of exit strip crown and edge drop under the same total rolling force; the strip crown and edge drop would be decreased if the intermediate roll shifting δi was decreased. Moreover, the rolling force distribution also was analyzed in details by changing the entry strip thickness, the entry strip crown and the intermediate roll shifting.

Asymmetric Shape Control Theory and Practice in Cold Strip Mills

In cold rolling process, asymmetric shape defects are still a common problem to strip quality. For the mills with inverse symmetry roll shifting system, different roll wear and thermal contour of top roll system and bottom roll system could cause asymmetric shape defects during shifting operation. In this paper, three dimension finite element simulation models of inverse shifting roll system were established to calculate the parameters and to analyze the effects. Based on the idea in the mill engineering that mill style option depended on the product grade, shifting weakness was evaluated and the opinion of limit shifting was suggested. To improve control effect to asymmetric shape defects in cold rolling, shape control system with asymmetric shape control ability is developed, including asymmetric edge drop control at upstream stands and asymmetric flatness control at last stand. The further improvement of asymmetric shape control theory and practice is the key way to reach the higher precision of shape quality in cold strip mills.

Nondestructive Evaluation Method of Average Grain Size in TWIP Steel by Laser Ultrasonic

TWIP steel has the characteristics of high elongation and high tensile strength at room temperature, and therefore it is widely used in the automobile manufacturing industry. Since the grain size has a very important influence on its mechanical properties and corrosion resistance it is significant to study the average grain size of TWIP steel. In this experiment, the specimens were heated to 700~1000°C and preserved for one hour, and the recrystallized structures with different average grain sizes were obtained. All the samples were tested by laser ultrasonic experimental platform and the standard sample was selected. Then the attenuation coefficients of remaining samples were compared with the standard samples by conventional methods. The results showed that the larger the difference between the average grain size of the test sample and the standard sample is, the greater the error of the test will be. The new evaluation model was established by the improved method, and the prediction error was reduced to 5.44~11.61%, which proved the effectiveness of the new method. In addition, laser ultrasonic testing has the advantages of high efficiency and no damage compared with traditional methods.

The Ultrasonic Detection of Macro-Inclusions in Steel

This paper studied the distribution of defects by ultrasonic testing and the source of the defect was verified by SEM/EDS. The results showed that the defects mainly distributed in inner and outer sides closed to the surface of the slabs. The number of the defects in inner side was 1.5~2 times of that in outer side. A window 40mm×180mm inclusion band in 1/8 of the inner side existed. The defects in hot-rolled plate mainly formed due to the bad plasticity and deformability inclusions, such as Al2O3, SiO2 and MgO·xCaO. So decreasing the inclusions in slab was important to decrease the defects in hot-rolled plate.

Design and Applications on Automatic Gauge Control and Automatic Tension Control for Continuous Tandem Cold Mill

This paper introduces the revamp of 1000mm cold rolling mills. For problems of low productivity and poor stability, a revamp of automatic gauge control (AGC) system and automatic tension control (ATC) system was taken. After the revamp, precision of gauge control and stability of tension control increase and the rate of malfunction was decreased obviously. The problems of former system are solved and the new system runs well.

The Modification of Leveling Model for Roller Leveler Based on Ansys/LS-DYNA

The paper researched a seven-roll leveler in the cross cut shearing line of a factory. An analytical model of the roller intermesh was established based on the elastic-plastic bend theory. It was known the maximal deformation of strip happened on the second leveler roll in the leveling process by the analysis of FEM simulation for the calculation results of analytical model. However, the restriction applied to the strip at the entrance side was smaller than expected, which caused the deformation was smaller than the calculated value of analytical model. Aiming at this program, combined with the analysis of FEM simulation, it was improved by adding the adjustment of the intermesh of first roll.