Gr2 (TA2)

The core advantage of Grade 2 (TA2) lies in its reasonable control of gap element content. With oxygen content controlled to ≤ 0.25%, the material exhibits good strength (tensile strength 345-450 MPa, yield strength 275-350 MPa) and good plasticity (elongation ≥ 20%) in the annealed condition, achieving an optimal balance between strength and plasticity. Compared to Grade 1 (TA1), Grade 2 has a strength improvement of approximately 100 MPa while still maintaining good cold formability, allowing for cold bending, stamping, simple deep drawing, and other forming operations. It is the most balanced grade in terms of comprehensive mechanical properties among industrial pure titanium grades, suitable for most industrial structural components and pressure-bearing parts.

Grade 2 (TA2) exhibits exceptional corrosion resistance in numerous corrosive media, primarily due to its ability to instantly form an extremely thin (several nanometers), dense, stable, and self-healing TiO₂ passivation layer on its surface. In media such as seawater, chloride solutions, wet chlorine gas, nitric acid, organic acids, and alkaline solutions, its corrosion resistance far exceeds that of stainless steel and copper alloys, with an extremely low corrosion rate. It is one of the few metal materials capable of resisting corrosion by wet chlorine gas, making it a core material choice for chlor-alkali industry, seawater desalination, and condensers in coastal power plants. Its corrosion resistance is essentially equivalent to Grade 1, and it is the most widely used corrosion-resistant material in the industrial pure titanium series.

The density of Grade 2 (TA2) is approximately 4.51 g/cm³, which is only 57% of that of carbon steel, giving it a natural lightweight advantage. Its specific strength is superior to most stainless steels and copper alloys, making it highly advantageous in weight-sensitive fields such as aerospace, marine engineering, and the automotive industry. Its modulus of elasticity is about 105 GPa, roughly half that of steel, endowing it with excellent vibration damping and impact resistance.

Grade 2 (TA2) exhibits excellent weldability and can be welded using various methods such as TIG, MIG, and plasma welding. The strength coefficient of the welded joint can reach over 90% of the base metal, making it one of the best weldable grades among titanium and titanium alloys. When welding, high-purity argon gas must be used to fully protect the high-temperature zone to prevent oxidation contamination that could lead to embrittlement. This alloy has good cold and hot working properties and can undergo various processes including forging, rolling, and stamping. However, its machinability is poor due to low thermal conductivity and a tendency to cause tool adhesion, requiring the use of carbide tools, low cutting speeds, and adequate cooling. Annealing can eliminate processing stresses and restore ductility, with typical annealing temperatures ranging from 650 to 750°C for recrystallization annealing.