Research On Sticking Mechanism And Influence Factors About TA2Industrial Pure Titanium Plates During Rolling

Titanium and its alloys have been widely used in aerospace and other fields due to itsexcellent performance. But it is also constrained by low processing efficiency and highproduction cost. One of the key factors leading to low processing efficiency is the stickingproblem between industrial pure titanium and the roll surface during the process of coldrolling. Focusing on this problem, the interfacial adhesion energies between Ti, Al, Cu,Mg and Fe and their internal binding energies were calculated. It is found that theinterfacial adhesion energy between Ti and Fe is not only greater than the internal bindingenergy of Ti, but also greater than the internal binding energy of Fe, which is differentfrom the other three metals. Therefore, fracture will occur on the deeper layer of Titaniumplate’s substrate with close contaction and relative movement between Fe and Ti surfaces.Then, the sticking situation of TA2cold-rolling is analyzed. It is found thatlubricating film is easier to rupture than other metals due to titanium’s unique properties,,which results in direct contact and sticking between roller and Titanium plate.Consequently, the sticking index is proposed to characterize the quantity of sticking, theimpact of draft rolling schedule, rolling speed, lubricant type on the degree of sticking isanalyzed. It is concluded that the cold-rolling speed of TA2should be lower than3m/s, thereduction rate of each pass should be less than20%.This paper analyzes the deformation and adhesive friction of three kinds of hot-rolledsheet, the sheet without oxide, with thick oxide, and with thin oxide, finding that the platewithout oxide and with thin oxide are more prone to internal friction. Titanium is a goodmaterial which has the properties of anti-oxidation, after descaling, thick enoughsecondary scale can not be quickly formed on the exposed surface of the plate, parts of theTitanium base will contact with the rolls directly. Therefor, after descaling, the plate canbe conducted pre-oxidation treatment to achieve the anti-sticking effect.This paper illustrates the important association between the sliding velocity with theadhesion on the roll surface, proposes a new calculation model of sliding velocity ofdeformation zone, Which enriches the "front slip and rear slip" part of the classic rollingtheory. Simulates the velocity field during cold rolling in industrial pure titanium plate. Using finite element software Deform-3D, obtains the simulation results of slidingvelocity in deformation zone at the stage of stable rolling, which is close to the results oftheoretical calculation. In addition, all of the deformation zone at the stage of biting arealmost the rear slip zone, at this time, the sliding velocity between roller and the plate isvery large, the plate,s surface temperature increases rapidly because of the friction, whichwill cause sticking possibly.