Research Of Titanium Strip Rolled By Steel Production Facilities In1880mm Hot Strip Mill In Baosteel

Titanium products mainly consist of plate and rolling strip. Rarely company can produce Titanium plate and no workshop can take this product to mass production. Special Steel Business Unit of Baosteel has studied the production of titanium and chose1880mm hot strip mill to produce the hot rolling coil of pure titanium.This thesis is hammer at getting the titanium rolling strip, mainly consists of follows.(1) Rolling scheduling and reheating. The transition should be considered when the production shift from steel to titanium occurs, because there is huge difference between the two kinds of products in reheating, rolling and coiling process. The reheating technique is researched. Low discharge temperature can ensure heating slab to avoid hydrogen absorbing and excessive oxidization. Furthermore, different heating zone should have different heating temperature and coefficient of excess air.(2) Detection during rolling. Titanium slab or stripe can’t be detect when it is transported on the rolling table and can’t be rolled consequently, since Titanium slab is heated to a low temperature and there is difference of heat radiation between steel and titanium. And thus the detector should be modified from steel detecting pattern to adapt the titanium detection.(3) Finishing rolling. The properties of titanium such as thermal expansion, heat conductivity, density, specific heat capacity, must be considered when the rolling model is established the temperature, thick&rolling-force, width calculation models in the process computer control system. Especially the thick controlling technology is developed, which is very different from carbon steel rolling. And then technological parameter of temperature, rolling speed, water using and ratio of screwing down of F1-F7is obtained by numbers of rolling experiment.(4) Coiling and surface quality. High accuracy of coiling temperature controlling is achieved, by means of genetic algorithms of laminar coiling controlling model. In order to coil the strip with high quality, the tension of mandrel, pinch roll and wrapper rolls is adjusted. After these works, the high quality surface titanium strip is gotten without contusion defect.Based on the works above, titanium strip with high quality of dimensions (thick, width, flatness and crown) and surface is produced efficiently and steadily. The strip with thickness from3.0to6.1millimeter was produce by312coils,3156.3tons totally.