WANG Yong-qin
,
LI Li
,
YAN Xing-chun
,
LUO Yuan-xin
,
WU Liang
钢铁研究学报(英文版)
Many strip materials are coiled after rolling process. The stresses are imposed on the material wound on the automatically controlled collapse mandrel under the coiling tension. The coiling process can be described by three typical cases: winding without automatic adjustment, winding with automatic adjustment and after mandrel removal. A new model of equations for predicting the stresses during the strip coiling process is built by consideration of the three cases respectively. By solving the equations of different typical cases, the radial stresses and tangential stress of the layers of coil can be calculated. Also, the coiling parameters, such as strip thickness, coiling tension and necking critical pressure, affecting the coil performance are investigated. It is believed that the present model can be used for design and control of the automatically controlled collapse mandrel.
关键词:
automatically controlled collapse mandrel
,
coiling process
,
critical pressure
,
radial stress
,
tangential stress
WAN Fei
,
WANG Yong-qin
,
QIN Shu-ren
钢铁研究学报(英文版)
The mechanism for heat transfer of radiation is usually adopted to heat strip in vertical continuous annealing furnace. The rate of heat transfer among strip and other objects can be hugely affected by the parameters of strip speed, geometry factors and radiating characteristic of surfaces of strip, radiating tubes and walls of furnace. A model including all parameters is proposed for calculating the heat transfer coefficient, predicting the strip temperature and boundary temperature of strip through analyzing these parameters. The boundary temperature is a important datum and different from average arithmetic value of temperature of strip and temperature in furnace. Also, the model can be used to analyze the relation for temperature of strip and heat transfer coefficient, total heat transfer quantity and heating time. The model is built by using the radiating heat transfer rate, the Newton′s law of cooling, and lumped system analysis. The results of calculation are compared to the data from production line. The comparisons indicate that the model can well predict the heating process. The model is already applied for process control in production line. Also, this research will provide a new method for analyzing the radiation heat transfer.
关键词:
vertical continuous annealing furnace (VCAF)
,
radiation tube section (RTS)
,
radiation heat transfer
,
heat transfer coefficient
,
heat transfer rate
