LIU Yun-fei
,
PENG Yan
,
LIU Hong-min
,
ZHANG Jian
钢铁研究学报(英文版)
According to the research on the deformation resistance and the ferrite transformation behavior of X80 pipeline steel by using Gleeble-3500 thermal simulator, a mathematical model of the α-phase start transformation temperature for high-Nb pipeline steel was established, based on the transformation kinetics and thermodynamics. The influence of deformation and cooling rate as well as Nb content on the α-phase starting temperature was thoroughly investigated. The results given by the model were in good agreement with the experimental results, which showed that the model could predict the α-phase starting temperature for high-Nb pipeline steel during cooling process.
关键词:
high-Nb pipeline steel
,
hot deformation
,
deformation resistance
,
cooling rate
,
ferrite transformation temperature
WANG Xuesong
,
PENG Yan
,
XU Lipu
,
LIU Hongmin
钢铁研究学报(英文版)
According to the character of the deformation zone on pair cross rolls, which is different from the regular 4-high mill, there are longitudinal and transverse two-way shear deformation in the deformation zone, the character of metal particles flowing velocity is more complicated than normal rolling. Comprehensive influences of normal stress and shear stress in rolling direction, width direction and thickness direction are considered. Establish the rolling force calculation model of PC hot strip mills. After the longitudinal and transverse discretization of deformation zone, the longitudinal and transverse distribution of rolling force is worked out by the differential method, then calculate total rolling force. Calculated results are verified by experimental data.
关键词:
PC rolling mill;rolling force;differential method
ZHANG Jian
,
PENG Yan
,
LIU Hong-min
,
LIU Yun-fei
钢铁研究学报(英文版)
Abstract： To investigate the wear resistance of ZG42CrMo in industrial application, the wear behaviors under different normal loads, sliding speeds and ambient temperatures were simulated by an MMU-5G abrasion tester to acquire the friction coefficients and wear rates, with the morphology of worn surface observed by scanning electron microscopy (SEM) and chemical composition of worn surface and debris analyzed by X-ray energy dispersive spectroscopy (EDS). Combine with the theory of tribology, finally the regular of environmental factors′ influence on material wear behaviors is determined. The results show that the increase of load decreases wear resistance significantly, when the pressure reaches a certain extent, severe spalling occurs on the worn surface; the changes of speed result in the changes of size of abrasive debris, and then effect the wear behaviors, in the increasing process of speed, the wear rate increases firstly and then decreases; the rise of temperature causes changes in wear mechanism, bring forth oxidation film on the worn surface, which leads to significant improvement of the wear resistance of materials under high temperature compared to that under low temperature.
关键词:
Key words: ZG42CrMo
,
wear resistance
,
normal load
,
sliding speed
,
ambient temperature
SUN Jian-liang
,
PENG Yan
,
LIU Hong-min
钢铁研究学报(英文版)
Take the moving strip between two stands of some cold tandem rolling mill in rolling process as subject investigated, according to the Poisson-Kirchhoff sheet theory, the vibration model of the moving strip in the rolling process was established. Model of distributed stress was built based on rolling theory. And then, vibration model of moving strip with distributed stress was established. The partial differential equation was discreted by Galerkin truncation. The natural frequency and stability of the moving strip were investigated and simulation in time domain was made by numerical method. Take the moving strip between the second stand and third stand of some 1660 tandem mill as subject investigated, distributions of stress, natural frequencies and stability of moving strip were determined under six different rolling conditions which are “uniform distribution of stress”, “flat roll flat”(crown of entrance strip and crown of exit strip are all 0 at the second mill), “flat roll convex”(crown of entrance strip is 0 and crown of exit strip is 20μ), “flat roll concave”(crown of entrance strip is 0 and crown of exit strip is -20μ), “convex roll flat”(crown of entrance strip is 20μ and crown of exit strip is 0) and “concave roll flat”(crown of entrance strip is -20μ and crown of exit strip is 0). At last, three-dimension dynamic simulation was made, the moving law of the strip was determined. This model can be used to study the stability of moving strip, depress the shape wave of strip and develop new rolling technology from the aspect of dynamics theory.
关键词:
Moving strip;Distributed stress;Galerkin truncation method;Poisson-Kirchhoff sheet theory;Stability
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
