JIAO Xiaohong
,
SHAO Liping
,
PENG Yan
钢铁研究学报(英文版)
To further improve the control accuracy for strip dimension of hot strip mills, an adaptive control scheme is investigated for a hot strip finishing mill based on the decentralization and coordination among the controllers of gauge, tension and looper. Consequently, the adaptive controller designed can regulate simultaneously the strip exit thickness, the strip tension and the looper angle to ensure better performance of the strip quality of finishing mills. Moreover, the control scheme is proposed in consideration of the essential nonlinearity and the unavoidable friction phenomena in the mechanical system, so the controller can be efficient in a wider range of working situations. The simulation results of a model obtained from a real hot strip finishing mill show the effectiveness of the proposed control scheme in comparison with the conventional control method.
关键词:
hot strip finishing mills; exist gauge; tension; looper angle; adaptive control
Author X.A. Zhang1)
,
H.Q. Xia1)
,
Z.T. Wu1)
,
Y.F. Han1)
,
R. Shi2) and G.X. Hu2) \= 1) Mechanical Properties Laboratory
,
Beijing Institute of Aeronautical Materials
,
Beijing 100095
,
China2) The State Education Commission Open Research Laboratory for High Temperature
金属学报(英文版)
Materials and Testing, Shanghai Jiao Tong University, Shanghai 200030, ChinaManuscript received 18 October 1998 The threestage creep behavior of DD3 single crystal superalloy had been studied. The results show that the creeprupture properties of DD3 single crystal satisfy the requirements for high performance turbine blade application. The influence of crystal orientation on the creeprupture property of DD3 single crystal was tested and discussed. An engineering criterion to evaluate the regimes of secondary and tertiary creep is proposed, and this method gives a reasonable result for practical applications. The fractography and TEM micrography of the tested specimens had been studied, and it is determined that the glidecontrolled creep is the basic creep mechanism of DD3 single crystal at intermediate temperature, but the thermally activated processes become dominant at higher temperature.
关键词:
threestage creep curve
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