ATI 30, CP Grade 1, ATI 40, CP Grade 2, ATI 55, CP Grade 3, ATI 70, CP Grade 4 or Commercially Pure, titanium grades (UNS R50250, R50400, R50550, R50700) are used where high ductility combined with excellent corrosion resistance, moderate strength, and good weldability are desired. The four grade numbers (ATI 30, 40, 55, 70) refer to the approximate minimum yield strengths for each grade. The different grades are characterized by differences in oxygen levels. These three titanium grades may be produced by single melt EB (electron beam) processing, or in a multiple melting practice with a final VAR (vacuum arc remelt). Typical product forms are billet, rolled bar, rod, and drawn wire products for applications such as airframe skin and structural components, cryogenic vessels, heat exchangers, chemical processing equipment, and medical and surgical device applications
SPECIFICATIONS
• ASTM Grades I, II, III, IV (ATI 30, 40, 55, 70)
• ASTM B 348 - Bars and Billets
• AMS 4921 - Bars, Wire, and Forgings
• ASTM F 67 - Unalloyed Titanium
• ISO 5832-2 - Unalloyed Titanium
PHYSICAL PROPERTIES
Melting Range: 3,000-3,040°F, (1,649 - 1,671°C)
Density: 0.163 lbs/in3; 4.51 gm/cm3
Beta Transus Temperature:
ATI 30 1,630°F ± 25F° (888°C ± 4C°)
ATI 40 1,675°F ± 25F° (913°C ± 4C°)
ATI 55 1,690°F ± 25F° (921°C ± 4C°)
ATI 70 1,740°F ± 25F° (949°C ± 4C°)
HEAT TREATMENT
Commercially pure titanium can be annealed by heating to 1,000 - 1,300°F (538 - 704°C) for 1/2 to 2 hours and air cooling.
Stress relief annealing can be achieved by heating to 1,000 - 1,100°F (538 - 593°C) for 30 minutes followed by air cooling.