1.What welding wire is matched for Grade 2 titanium?
For welding Grade 2 commercially pure titanium, the most commonly used and recommended matching welding wire is ERTi-2 (AWS A5.16 standard), which is chemically and mechanically equivalent to Grade 2 base titanium.
Reasons for matching ERTi‑2 wire:
It has the same chemical composition as Grade 2 base metal, especially controlled levels of oxygen, iron, and impurities.
Ensures the welded joint has similar ductility, formability, and corrosion resistance as the base metal.
Suitable for all common welding processes: TIG (GTAW), MIG (GMAW), and plasma welding.
In some cases where slightly higher strength is acceptable, ERTi‑3 can also be used, but ERTi‑2 is still the standard and preferred choice for Grade 2 titanium welding.
2. Does the corrosion resistance of Grade 2 welded joints decrease?
Under proper welding conditions, the corrosion resistance of Grade 2 welded joints does not decrease significantly and remains almost the same as the base metal.
Detailed explanation:
Grade 2 is pure titanium, which relies on a thin, stable, and self-healing TiO₂ oxide film for excellent corrosion resistance.
As long as welding is performed under adequate argon shielding (to protect the weld and heat-affected zone from oxidation, contamination, and gas absorption), the weld surface will quickly reform a protective oxide layer.
If the weld is contaminated by oxygen, nitrogen, hydrogen, carbon, or other impurities during welding (e.g., insufficient shielding, unclean surface), the weld may become hard, brittle, and its corrosion resistance will decrease.
In normal industrial production with standard welding procedures, Grade 2 welds maintain excellent corrosion resistance in seawater, oxidizing acids, organic acids, and alkaline environments.
Conclusion:
With correct welding practice and full argon protection, Grade 2 welded joints maintain excellent corrosion resistance, almost equal to the base metal.
Only poor welding or contamination will cause reduced corrosion resistance.
