Abstract: Temperature field calculation of strip is an important premise of ensuring shape quality, dimensional accuracy and structure property in hot strip mills, its numerical efficiency and accuracy are the main factors that have restricted the application of online calculation. On the basis of the analysis of existing models, considering heat radiation of strip to surrounding environment, convectional heat exchange between strip and liquid medium all round, heat transmission between strip and work roll, deformation heat of strip and friction heat between strip and work roll in the process of hot rolling, based on the physical parameters and reasonable assumptions, the general algorithm of strip temperature field in finishing mill is established by using two-dimensional alternating difference method. Combined with the actual production conditions of hot strip mill, an online calculation model of strip temperature field in finishing mills is established by C++ software, which can be used to calculate temperature distribution of strip cross-section out of each stand. The feasibility of online application of rapid temperature field model is validated by contrasting the transverse temperature distribution between calculation values and actual measured values, which reflects from that the overall distribution trend is consistent, the temperature difference is controlled within 15 ℃, the mean relative deviation is only 0.56%, and the computing time is only 46 ms.

Key words: hot strip mills;finishing mills;temperature field;online;two-dimensional alternating difference method