Titanium flange, titanium alloy flange performance characteristics and hot processing related matters needing attention.
Hot processing, mainly forging, rolling and extrusion is the basic production method of semi-finished products and products of titanium flange. In view of the sensitivity of titanium flange structure to the root strength of hot processing technology, the correct selection and mastery of process parameters is not only very important to ensure the dimensional accuracy of the product, but also a key factor for the internal quality of the product.
Compared with general metal structure materials, the thermal processing of titanium flange is characterized by great deformation resistance and narrow deformation temperature range. Titanium with hexagonal crystal structure is not easily deformed. In order to improve the plasticity, it is necessary to heat the metal into the b phase above the phase transition point and conduct the so-called b processing. But, because of the large titanium flange overheating tendency of high temperature heating will cause b of grains growing up sharply, but if the deformation is insufficient, rough widmanstatten structure is formed after cooling will obviously reduce the period and the fatigue strength of alloy, and on the overheating of tissue in the subsequent heat treatment of difficult to eliminate, so the production of finished products or finished products before a fire hot working starting temperature regulation in the critical point of Tb. Because the deformation resistance of titanium flange is very sensitive to the reduction of deformation temperature or the increase of deformation rate, the temperature of stop forging can not be too low. Due to the restriction of these two factors, the processing temperature range of most finished titanium flanges is limited to between 800 ℃ and 950℃, which is not easy to grasp. However, the temperature range can be extended to 850-1150 ℃ for the opening of the ingot, and the temperature can be lowered successively in the subsequent processing.
Titanium flange alloy thermal conductivity is poor, in the rapid deformation, the workpiece core temperature rises fast, due to the slow heat transfer and easy to cause overheating, and the workpiece surface temperature is low, and easy to form surface cracks, so the processing process should pay attention to grasp the deformation rate and deformation.
