A new roll shifting strategy with varying stroke and varying step was investigated,Two characteristic parameters including cat ear height and gap contour smoothness were introduced to assess the effect of shifting str...A new roll shifting strategy with varying stroke and varying step was investigated,Two characteristic parameters including cat ear height and gap contour smoothness were introduced to assess the effect of shifting strategy on roll wear,and the relation between characteristic parameters and shifting strategy was established.Both varying stroke and varying step can reduce cat ear height and gap contour smoothness,so the shifting strategy with varying stroke and varying step is better than the one with either varying stroke or varying step,Based on the effect of shifting control parameters on characteristic parameters of roll wear,the selection principle of these shifting control parameters was gained.A case study was conducted to validate the proposed roll shifting strategy,reducing uncontrollable quartic loading gap contour,improving strip profile and extending rolling length of a rolling campaign.展开更多
Considering the effect of work roll shifting on roll temperature field,a finite difference method of PR format for roll temperature field was presented,which can meet the requirements of accuracy and speed of online c...Considering the effect of work roll shifting on roll temperature field,a finite difference method of PR format for roll temperature field was presented,which can meet the requirements of accuracy and speed of online calculation.The step-by-step accumulation method was used to simulate the roll temperature field and thermal crown,and the evolution of roll thermal crown in a rolling campaign was studied.And then,the effects of strip width,rolling rhythm and work roll shifting on roll thermal crown were analyzed.It is found that work roll shifting can disperse the thermal expansion of the roll body especially the edge to make roll thermal contour uniform.The effect of work roll shifting on roll thermal crown is mainly concentrated in regions around twice of roll shifting stroke,and the change range of roll thermal crown is±30μm or so in the same roll body location.展开更多
An optimization solution to roll shifting strategy for alternately rolling campaign is presented. All the strips in a rolling campaign are divided into narrow strips and wide ones, and shifting position of narrow stri...An optimization solution to roll shifting strategy for alternately rolling campaign is presented. All the strips in a rolling campaign are divided into narrow strips and wide ones, and shifting position of narrow strips is obtained by the recursive method, and then shifting position of wide strips is optimized by NSGA-II which is a multiobjective genetic algorithm. For wide strips, a multi-objective optimization model of roll shifting strategy is pro posed, which takes 3 wear contour factors including edge smoothness, body smoothness and edge drop as optimization objectives. The Pareto optimal front of roll shifting strategy can be gained quickly by NSGA-II, which suggests a series of alternative solutions to roll shifting strategy. Analysis shows that the conflict exists among the 3 objectives. The final optimal solution is selected from the Pareto optimal solutions by the weighted-sum decision-making method. Industrial production proves the validity of the solution, and it can improve strip profile of alternately rolling, reduce strip edge wave, and extend the rolling miles of rolling campaigns.展开更多
基金Project(50974039) supported by the National Natural Science Foundation of China
文摘A new roll shifting strategy with varying stroke and varying step was investigated,Two characteristic parameters including cat ear height and gap contour smoothness were introduced to assess the effect of shifting strategy on roll wear,and the relation between characteristic parameters and shifting strategy was established.Both varying stroke and varying step can reduce cat ear height and gap contour smoothness,so the shifting strategy with varying stroke and varying step is better than the one with either varying stroke or varying step,Based on the effect of shifting control parameters on characteristic parameters of roll wear,the selection principle of these shifting control parameters was gained.A case study was conducted to validate the proposed roll shifting strategy,reducing uncontrollable quartic loading gap contour,improving strip profile and extending rolling length of a rolling campaign.
基金Sponsored by National Natural Science Foundation of China(51205336)Fujian Natural Science Foundation of China(2013J05086)
文摘Considering the effect of work roll shifting on roll temperature field,a finite difference method of PR format for roll temperature field was presented,which can meet the requirements of accuracy and speed of online calculation.The step-by-step accumulation method was used to simulate the roll temperature field and thermal crown,and the evolution of roll thermal crown in a rolling campaign was studied.And then,the effects of strip width,rolling rhythm and work roll shifting on roll thermal crown were analyzed.It is found that work roll shifting can disperse the thermal expansion of the roll body especially the edge to make roll thermal contour uniform.The effect of work roll shifting on roll thermal crown is mainly concentrated in regions around twice of roll shifting stroke,and the change range of roll thermal crown is±30μm or so in the same roll body location.
基金Item Sponsored by National Natural Science Foundation of China(50974039)
文摘An optimization solution to roll shifting strategy for alternately rolling campaign is presented. All the strips in a rolling campaign are divided into narrow strips and wide ones, and shifting position of narrow strips is obtained by the recursive method, and then shifting position of wide strips is optimized by NSGA-II which is a multiobjective genetic algorithm. For wide strips, a multi-objective optimization model of roll shifting strategy is pro posed, which takes 3 wear contour factors including edge smoothness, body smoothness and edge drop as optimization objectives. The Pareto optimal front of roll shifting strategy can be gained quickly by NSGA-II, which suggests a series of alternative solutions to roll shifting strategy. Analysis shows that the conflict exists among the 3 objectives. The final optimal solution is selected from the Pareto optimal solutions by the weighted-sum decision-making method. Industrial production proves the validity of the solution, and it can improve strip profile of alternately rolling, reduce strip edge wave, and extend the rolling miles of rolling campaigns.
