Specific use cases of titanium plates in the electric power industry

In recent years, titanium plate has been more and more widely used in the electric power industry. Combined with the excellent specific strength, corrosion resistance and good fatigue performance of titanium plate, titanium plate has been highly concerned by professional engineers and manufacturers in steam turbine blades, generator guard rings and other application scenarios.

Due to its high specific strength, good fatigue performance and corrosion resistance, titanium alloy plate is also suitable for steam turbine blades, mainly the last few stages of the low pressure section. Usually turbine blades are made of martensitic chromium stainless steel. For a high speed steam turbine, the steel blades are subjected to tremendous centrifugal force.

In addition, there are often chloride-phase sulfides in water vapor, which is caused by condenser leakage and other reasons. These media lead to pitting corrosion on the surface of the blade, and crevice corrosion is formed between blade root and blade tip or in the tensile reinforcement, and the corroded part will become the crack source. The fatigue properties of Crl3 steel are also not ideal. In the corrosive environment with saturated sodium chloride solution, especially in the case of low pH and dissolved oxygen, the fatigue strength of Crl3 steel decreases greatly. Using titanium blades directly in place of steel blades according to the original geometry, the situation will be greatly improved. The titanium blade is light, and the centrifugal force on the blade root can be reduced by 40% at the same speed. In addition, the corrosion resistance of titanium blades to salt vapor is much better than that of steel, and the fatigue performance of Chingan gold is also higher than that of stainless steel.

In air, the fatigue strength of Ti-6Al-4V alloy is about 30% higher than that of Cr13 steel, while the fatigue strength of Crl3 steel decreases by 2/3 -- 4/5 in sodium chloride melt. In contrast, the fatigue property of titanium alloy is not affected. Therefore, considering the advantages and disadvantages of fatigue properties under corrosion conditions is the most important factor to replace titanium steel.

Titanium plates can also be used as generator retainers. In the whole turbine generator system, the guard ring is an important part. The requirements of large generators for the guard ring are high strength, good fracture resistance, not sensitive to stress corrosion cracking in water, and should be non-magnetic. The current retaining ring is made of austenitic Fe-MN-Cr alloy, which has a strong tendency to stress corrosion cracking and has problems in achieving high strength reliability.