Ti- (0.8 ~ 6%) Nb alloy pipe is titanium metal as the matrix, adding a small amount of niobium metal, through the solution strengthening method to improve the mechanical properties of niobium metal, the shear strength and tensile strength are higher than pure titanium, the tensile strength is increased by 10 ~ 20%, and maintain good plasticity and forming properties, cold working performance is excellent. By adding niobium, the corrosion resistance of titanium can be further improved, and the corrosion resistance range of titanium can be expanded.
Has the following advantages:
1. With excellent corrosion resistance: the alloy sheet can further improve the corrosion resistance of titanium. Under the same conditions, the corrosion rate of Ti is an order of magnitude larger than that of Nb, and the corrosion resistance of niobium is much higher than that of titanium. In Ti-Nb alloy, with the increase of niobium content, the corrosion resistance will also increase, when the niobium content increases to 35-45%, the corrosion resistance and pure niobium equivalent, when the niobium content continues to increase, the corrosion resistance will not increase, there may be a downward trend. Therefore, even adding 0.1 ~ 4.9% niobium in titanium will further increase the corrosion resistance of titanium.
2. While not reducing the plasticity, it has a certain strengthening effect, and the comprehensive index of strong plasticity is good. The annealed strength of pure titanium plate (generally TA1) is generally 250 ~ 320MPa, the elongation is 55 ~ 60%, and the cup-tip value is not less than 9.5mm. The tensile strength of the cold-rolled sheet after annealing is good, the tensile strength is 380 ~ 500MPa, the non-proportional extension strength is 320 ~ 450MPa, the elongation is 40 ~ 55%, and the cup bead value is not less than 9.5mm.
3. The metal microstructure is good, and the grain is smaller than that of pure titanium plate, and the organization is more uniform. Because a small amount of niobium is added to pure titanium, the alloy sheet of the invention is conducive to refining the grain, improving the homogeneity of the structure, and making the metal microstructure better. It has good heat transfer efficiency. Due to the addition of a small amount of niobium, the thermal conductivity of titanium can be further improved, and the solid solution strengthening can further thin the wall thickness design of the plate, so that the heat transfer efficiency of the heat exchange plate will be further improved.
