Papers by Keyword: Cooling Strategy

Abstract: Backward Ultra-fast cooling (UFC) plays a key role in low-cost dual-phase steels production. Cooling process control system for backward UFC was developed to meet the process requirements. Basing on basic theory of heat transfer, cooling control model was established to accomplish temperature calculation. To deal with the influence of technological conditions fluctuations an adaption system, including self-learning function and feedback function was proposed to intelligently realize temperature correction. The developed cooling strategy can achieve diversified cooling path control. The controlling of significant technological parameters, including cooling rate and air cooling time for dual-phase steels, was also accomplished. Furthermore, flexible and diversified UFC strategies were developed aiming at high temperature precision and low temperature deviation control in thickness direction. The system has been applied successfully in dual-phase steel production with high stability and reliability. The precision of medium temperature (MT) can be controlled within ±10°C, and the UFC delivery temperature (UFC-T) can be limited within ±30°C of the target values.

Abstract: According to the arrangement of laminar cooling equipment in Desheng 1150mm hot strip mill, two-dimensional finite difference method has been used for coiling temperature online control model basing on the analysis of heat transfer characteristics, practical data are used to optimize water heat coefficient for self-learning as amended, this model are used to calculate the steel temperature change and distribution in the process of laminar cooling. Analysis of different cooling strategies on the cooling rate and organization of steel show that: In the same number of opened cooling tubes, the cooling capacity is not the same in the different strategies, the cooling to back direction is the strongest, followed by intermittent cooling, the cooling to front direction is the smallest. Cooling strategy was applied to the scene and simulated results match with the actual observation. The system has a wide range of cooling rate adjustment, the operation and control is well, which meet to the development and the requirements of new varieties.

Abstract: The text takes Z-Axis of precision machine tool as study object, and proceed the thermal character's experiment of Z-Axis feed system in different working condition (different Cooling strategy, different Feeding speed, load or not). The data of experiment shows the higher of the feed speed, the more heat is generated. Position accuracy can be increase by apply the right load and load is nearly none business with temperature rise. Cooling strategy is nearly none business with temperature rise and may cause the discretization of position accuracy.

Abstract: This study focused on the side milling surface roughness of titanium alloy under various cooling strategies and cutting parameters. The experimental results show that the cooling strategies significantly affect the surface roughness in milling Ti-6Al-4V. Surface roughness (Ra) alterations are investigated. Cutting fluid strategy made nearly all the smallest and most stable roughness values. The surface roughness values produced by all cooling strategies are obviously affected by feed, radial depth-of-cut and cutting speed. However, axial depth-of-cut has little influence.

Abstract: Based on optimization setup technology, an online adaptive calculation method for improving accuracy of strip coiling temperature control on the run-out table (ROT) has been developed and implemented in hot strip mill (HSM). Multi-objective control strategies, which include coiling temperature, middle target temperature and appropriate cooling rates have been finalised. Cooling strategies, elements tracking, and dynamic correction are employed in the control system. In addition, the model optimization and soft-measure method are also introduced in the study. Rolling tests with various grades of steel covering a wide range of thickness show that the developed model can improve the accuracy of coiling temperature control to obtain an uniform mechanical properties. Good correlation has been found between the predicted temperatures and the actual coiling ones.