Gr3 (TA3)

The core advantage of Gr3 (TA3) lies in its highest controlled interstitial element content. With an oxygen content controlled to ≤ 0.35%, the material exhibits the highest strength in the annealed condition (tensile strength 450-590 MPa, yield strength 380-450 MPa), making it the strongest grade in the industrial pure titanium series. Compared to Grade 2 (TA2), Grade 3 offers an increase in strength of approximately 100-140 MPa while still maintaining good ductility (elongation ≥ 18%), allowing for cold bending, stamping, and other forming operations. It is the strongest and highest-pressure-bearing grade in the industrial pure titanium series, suitable for high-strength structural components and high-pressure pressure-bearing parts.

Gr 3 (TA3) exhibits exceptional corrosion resistance in a variety of corrosive media, with its core mechanism being the ability to instantly form an extremely thin (several nanometers), dense, stable, and self-healing TiO₂ passivation film 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 withstanding 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 basically comparable to Grades 1 and 2, and it is the highest-strength corrosion-resistant material among industrial pure titanium grades.

The density of Gr 3 (TA3) 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 Grade 1 and Grade 2, 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.

Gr 3 (TA3) 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 stick to tools, requiring the use of carbide cutting tools, low cutting speeds, and adequate cooling. Annealing can eliminate processing stresses and restore ductility, with typical annealing temperatures for recrystallization ranging from 650 to 750°C.