The quality of Ti-13Nb-13Zr titanium plate is largely determined by the titanium plate manufacturer's smelting process, including the chemical composition of titanium, the cleanliness of titanium water (gases, harmful elements, inclusions) and the quality of the cast billet (compositional segregation, decarburization, and its surface condition), which are precisely the key control points of the smelting operation.
In addition, industrial titanium plate also requires sufficient hardenability to ensure that the entire spring cross-section to obtain uniform microstructure and mechanical properties. The main cause of fatigue cracks is oxide inclusions in titanium, and D inclusions are more harmful to fatigue life than B inclusions. Therefore, foreign titanium factories and automobile factories on the industrial titanium plate in the oxide inclusions put forward higher requirements, such as the Swedish SKF standard requirements of titanium in the oxygen content of less than 15 × 10-6, D inclusions lower than B inclusions. Especially Al2O3 and TiN inclusions on the fatigue life of titanium springs is very harmful. In order to produce high-quality industrial titanium plate, in the past, usually using electric furnace - electroslag remelting or vacuum arc remelting and other special smelting methods.
Because titanium plate, titanium bar has special physicochemical properties, so its welding process and other metals are very different. Titanium welding is through the inert argon gas on the welding zone for effective protection of the TiG welding process, argon gas in the use of the bottle before checking the factory certificate to verify the purity of the argon gas index, and then check the bottle valve for leakage or malfunction.
Titanium plate and titanium bar welding must be ensured:
The metal in the welding zone is not contaminated by the active gas N0H and harmful impurity elements CFeMn, etc. above 250℃. Purity shall not be less than 99.98% water content is less than 50Mg/m32 Argon: industrial grade 1 pure argon.
Can not form coarse crystal organization. Welding process shall be in accordance with the predetermined construction sequence, can not produce large welding residual stress and residual deformation. So. Strictly according to the process quality management standards, the implementation of the whole process of quality control. Make people, machines, materials, law factors are in a good state of control, so that in a reasonable period of time, to ensure the welding quality of titanium tube.
