A notable feature of titanium plates is their strong corrosion resistance, which is due to their great affinity for oxygen. It can form a dense oxide film on its surface, which can protect titanium from medium corrosion. It has good stability in acidic, alkaline, neutral saline solutions and oxidizing media, and is better than existing stainless steel and other commonly used non-ferrous metals in corrosion resistance.
The quality of titanium plate largely depends on the smelting process of the titanium plate manufacturer, including the chemical composition of titanium, the cleanliness of titanium water (gas, harmful elements, inclusions), and the quality of cast slab (composition segregation, decarburization, and surface conditions), which are the key control points of smelting operation.
In addition, industrial titanium plate also requires sufficient hardenability to ensure uniform microstructure and mechanical properties of the whole spring cross-section. The main reason for fatigue cracks is oxide inclusions in titanium, and the damage of type D inclusions to fatigue life is greater than that of type B inclusions. Therefore, foreign titanium factories and automobile factories put forward higher requirements for oxide inclusions in industrial titanium plates. For example, the Swedish SKF standard requires that the oxygen content in titanium be less than 15 × 10-6, and class D inclusions are lower than class B inclusions. Especially Al2O3 and tin inclusions do great harm to the fatigue life of titanium springs. In order to produce high-quality industrial titanium plates, special smelting methods such as electric furnace electro slag remelting or vacuum arc remelting were usually used in the past.
Because titanium plate has special physical and chemical characteristics, their welding process is very different from other metals. Titanium welding is a TIG welding process that effectively protects the welding area with inert argon. Before using argon, check the factory certificate on the bottle body to verify the purity index of argon, and then check whether the bottle valve leaks or fails.
When welding titanium plates, the following must be ensured:
The metal in the welding area shall not be polluted by the active gas n0h and the harmful impurity element clean above 250 ℃. Argon with purity not less than 99.98% and water content less than 50mg / M32: industrial grade I pure argon.
A coarse crystal structure cannot be formed. The welding process shall be carried out according to the predetermined construction sequence, and no large welding residual stress and residual deformation shall be generated. Therefore, the quality control of the whole process shall be carried out in strict accordance with the procedure quality management standards, so that the factors of human, machine, material, and method are under good control, so as to ensure the quality within a reasonable construction period.