پيش بيني توزيع دماي ورق نورد گرم در فرآيند نورد نهايي

چكيده انگليسي :

Isfahan University of Technology T Predict tion of Te emperature Distrib bution of H Rolle Strip Hot ed in the Finishin Mill e ng Moham mmad Javad Amini mj a amini@me iut t ac ir March 2011 M Deepartment of Mechanical Engineer f ring Isf fahan Unive ersity of Tec chnology Isfahan 8415 56 83111 I Iran De egree M Sc c La anguage Fa arsiSupervis sor Dr Ahm Saboonch ahmadsab@ mad hi @cc iut ac ir AbstractIn the process of hot s strip rolling prediction of th temperatur distribution within the st along the length of he re n tripthe finisshing mill is essential be ecause tempe erature is the leading par e rameter contr rolling the ki inetics ofmetallurggical transformmations Phys sical propertie as well as the final dime es t ensions of the strip are rela ated to thetemperatu distributio within the metal being r ure on rolled Proper functioning of set up mod in a hot strip steel r delsmill requ uires reliable prediction o strip tempe of erature Temp perature pred diction is part ticularly impo ortant foraccurate calculation of rolling force because of strong depen ndence of yiel stress and strip microstr ld ructure ontemperatu In this th ure hesis a compre ehensive model is presented for predictio of tempera d on ature distributi of hot ionrolled str in the finis rip shing mill Th new model predicts the strip temperatu evolution from the finis he s ure shing millentry to t finishing m exit This model is thr the mill s ree dimension and none o the mechan nal of nisms of heat transfer is tomitted velocity field in the conta area is mo d act odeled precise and the co ely omponent of v velocity along the strip gthickness is not neglec s cted Heat trannsfer of work roll is solved with the heat transfer of str simultaneo rip ously as tocalculate the strip temmperature mor accurately An important parameter in the operatio of hot rollin mill is re t n on ngthe coolin mechanism of work roll In the bound ng m l dary condition for water sp n pray paramete such as spr angle ers raythe angle of spray imp on work r e pact roll the distan of header from work roll and water p nce pressure are va ariable Inrolling th work roll i used as a to to deform the strip resu he is ool ulting in rollin contact bet ng tween the roll and strip land creat ting thermal r resistance along the interfa A wide range of mode ace r eling approaches or correla ations hasbeen dev veloped to stu the interfa heat trans phenomen during roll udy ace sfer na ling In this thhesis the rationale andformulati of the mos frequently a ion st adopted appro oaches in mod deling of the ro oll strip conta region are reviewed actThe asso ociated advant tages and disa advantages of three major approaches ar specifically discussed Th model f a re y hisalso base on empirical relationship in order to take into acc ed ps o count heat transfer coefficients in every region ofthe strip interface fric ction factor in the roll gap pressure variation in conta area emiss n act sivity and tem mperature dependan physical pro nt operties of meetals it takes i into account th heat genera by the fri he ated ictional sliding between gstrip and work roll de eformation hea in the bite r at region heat loosses due to ro chilling rad oll diation and coonvection rolling sp peed continuuous thicknes reduction d ss during rolling growth of oxide layer a its effect on strip g and ttemperatu Using a finite volume approach t governing differential equations as well as the boundary ure e the gcondition are discret ns tized which are then solv numerical to predict the tempera ved lly t ature distributtions Thestability o the solution was examined by changin the grid siz in addition the numeric results are validated of n ng zes n calagainst ppublished wor in the lite rk erature for cer rtain special operating con nditions The impact of ro speed e ollfrictional sliding and d l deformation heat oxide lay and conduc yer ction along the length and w width of the slab on thedistributi o

اميني، محمد جواد

پيش بيني توزيع دماي ورق نورد گرم در فرآيند نورد نهايي

توزيع دماي ورق , مدل سازي گرمايي , مدل سازي عددي