Titanium and titanium alloy bars of small size are generally produced by rolling. However, in the process of heating, rolling and heat treatment, due to uneven distribution of temperature and plastic deformation, as well as shear, transportation and stacking, various degrees of bending often occur. At this time, straightening treatment must be carried out to ensure that the bending degree of the bar can meet the use requirements.

The commonly used straightening methods for titanium and titanium alloy bars are pressure straightening and roll straightening, while the roll straightening is generally used for small titanium bars, which has high efficiency. However, for small sized titanium and titanium alloy bars, after many times of straightening, the ideal effect is still not achieved, and even the problem of direct fracture in the straightening process often occurs. By analyzing the hot straightening of titanium and titanium alloy small size bars, titanium alloy bar manufacturers put forward a simple, convenient and low-cost heating straightening method.

The room temperature elastic modulus of common titanium and titanium alloys is mostly lower than 120GPa, so titanium and titanium alloy bars will have large elastic deformation under low stress conditions, with large rebound and difficult to straighten; And the yield ratio of many titanium alloys is between 0.9~1, which is very easy to fracture during straightening. Therefore, titanium and titanium alloy bars generally need to be hot straightened to ensure the straightening effect.

At present, the consumption of titanium and titanium alloy is still relatively small. In the actual production process, the order quantity of a single batch is often only several hundred kilograms, or even dozens of kilograms, and there are many specifications. In general, plants are often equipped with a heating furnace with large heating capacity, which can load several tons or dozens of tons at a time. Therefore, when heating and straightening titanium and titanium alloy bars, the heating cost is often high. Secondly, the straightening equipment arranged in general factories is often far away from the heating facilities. When titanium and titanium alloy small specification bars are heated and then transferred to the straightening equipment, the temperature of the bars is often seriously lost, resulting in a significant reduction in the straightening effect. If the corresponding heating and straightening facilities are specially built for the straightening of titanium and titanium alloy bars, the actual equipment utilization rate is low and the economy is poor.

Therefore, how to select an efficient and economical hot straightening method for titanium and titanium alloy bars has become an urgent problem to be solved.