The Technical Reaches Of The Stretch, The Bend And The Level Of Titanium Strip

With the development of industry and the increasing requirement of the strip flatness, and because of titanium material’s high yeild strenght, low elasticity modulus and obvious subsequent processing springbuck phenomenon, the traditional roller straightening machine has the limitation of structure and processes, which cannot straighten three-dimensional shape defects of high yield-strangth ratio strips(wave-shaped edges and intermediate buckling, etc.). The stretch bending technology can effectively improve and eliminate the strip flatness defects, so as to improve the quality of the thin strip flatness, which has been increasingly used in strip finishing area. Therefore, the research on stretch bending technology of titanium strip has important theoretical and practical significance.With background of one titanium strip workshop’s stretch bending straightening machine, based on the theory of stretch bending straightening, combining the chemical composition of the material and the strenght level, this paper uses only stretch methood to straighten strips when stips have low yeild strenght and good original flatness. As to high yeild strenght strips, the stretch bending technology is used to improve strip flatness. By studying the influence of tensile force, straightening reduction, ductility, etc. on strip flatness and designing technological parameter to improve strip flatness, the results show that: In the process of pure tension straightening, with the condition of cross section area changing during 300~2500 mm2 and TA1 yeild strenght changing during 160~180KN, good flatness TA1 strip can be obtained. In the process of stretch-bending straightening, increasing straightening reduction can not only decrease tensile force, but also have better result than adjusting tensile force. Adjusting straightening reduction during 4.0mm~15.0mm and keeping straightening force during 65~372KN, titanium strip flatness can reach to ±3mm/m. Good flatness strip can be obtained by combining resonable straightening reduction and straightening force.The study title of this article is closely connected to workshop production, provides basic theory to stretch-bending straightening, and obviously improves strip flatness. The results of this stuy can be used to industrially product pure titanium strips by stretch-bending straightening.