Pack-rolling process of ultra-long titanium sheets

In this paper, pack-rolling, a special way for assembling and welding of packs equipped with a number of grinding units,is introduced to produce the ultra-long titanium sheets. The surface treatment process, the assembly welding mode as well as the rolling process were studied. The results show that surface treatment can prevent adhesion of titanium sheets, and lowering the rolling temperature can significantly improve the interface quality. Changing rolling direction before the second hot rolling and increasing pass reduction during rolling can effectively reduce the camber of sheets, and improve the flatness of sheets; Meanwhile the ultra-long titanium sheets with a size of 4mm× 1350mm× ≥1l000mm are obtained. In addition, the variations of thickness along the length of titanium sheets are less than 0. 13mm. After annealing at 650°C for 1 hour, the grain size of titanium sheets is about 20∼30μm and mechanical properties meet the requirements of the standards GB/T 3621 and ASTM B265.