Straightening on titanium rod

Industry thought alloy bars having a "shape memory", that material could have been straightened by straightening, and over time it according to the original curvature. In fact, people think that all have shape-memory alloy is a misunderstanding. In the alloy system memory, the only In-Ti, Ti-Ni, Ti-Ni-Pd, Ti-Nb alloys containing titanium these types, only first discovered memory alloy like nickel - titanium alloy (50% Ti + 50 % Ni), we will mistakenly believe that a titanium bar stock with shape memory characteristics. Why, then, would have been straightening alloy bars, over a period of time according to the original curvature it out?
This is because the core of the metal rod has its own original bent, without any change in the straightening process. From the surface, even if the entire roundwood has been straightened and resilient core but can not get straightened. Otherwise it would not be called elastic core of. This time, straightening belong to a certain amount of anti-bending and straightening bent elastic recovery after the remaining zero curvature sometimes obtained a balance of straightening is resilient core of elastic recovery potential and peripheral metal Instead of excessive bending of the potential direction of a balance of equal size. This relative balance when changes in environmental conditions such as temperature change, external change, after the time change may imbalances bent. Thus, rod straightening, especially raw bar straightening a bent state serious, should not cause distortion of adoption under section inflection amount of suitable size to make it resilient core to a minimum, which is conducive to straightening quality of persistence. So these problems are due to the influence of the resilient core of straightening quality caused. Had straightening experience knows Straightening easier than bar, which did not affect the main reason is the core of the metal pipe on the overall flatness of the straightening process, which is why there is no Titanium tube fittings called "memory Features "Reasons