Seawater General Corrosion & ErosionSeptember 26, 2016
Basic Titanium MetallurgySeptember 26, 2016
Commercial Titanium Alloys
Ti Grade 1
Lower strength, softest, non-alloyed Ti grade with highest ductility, cold formability, and impact toughness with excellent resistance. Mildly reducing to highly oxidizing media with or without chlorides and high weldability.
Ti Grade 2
Moderate strength non-alloyed Ti with excellent weldability, cold formability, and fabricability.
Ti grade for industrial service with excellent resistance to mildly reducing to highly oxidizing media Welded Tubing, HE HR, MI, NS, with or without chlorides. Approved for our service use under the NACE MR-01-75 Standard.
Ti Grade 3
Slightly stronger version of Gr. 2 Ti with similar corrosion resistance with good weldability and reasonable cold formability/ductility.
Ti Grade 4
Much stronger & high interstitial version of Grades 2 and 3 Ti with reasonable weldability and reduced ductility and cold-formability.
Ti-0.15Pd (Grade 7) [Ti-Pd]
Most resistant Ti alloy to corrosion in reducing acids and localized attack in hot halide media with physical/mechanical properties equivalent to Gr. 2 Ti and excellent weldability/fabricability.
Ti-0.15Pd (Grade 11)
Most resistant Ti alloy to corrosion in reducing acids and localized attack in hot halide media with physical, mechanical, and formability properties equivalent to Gr. 1 Ti (soft grade) and excellent weldability.
Ti-0.1Ru (Grade 26) [TiRu-26®]
Lower cost Ru-containing alternative for Ti Gr. 7 with equivalent physical/mechanical properties and fabricability with similar corrosion resistance.
Ti-0.1Ru (Grade 27) [TiRu-27®]
Lower cost Ru alternative for Ti Gr. 11 with equivalent physical/mechanical properties (soft grade) and fabricability. Similar corrosion resistance.
Ti-0.3Mo-0.8Ni (Grade 12) [Ti-12]
Highly weldable and fabricable. Ti alloy offers improved strength and pressure code design. Allows for hot brine crevice corrosion and acid reduction resistance compared to Ti Grades 1, 2, and 3. Approved for sour service use under the NACE MR-01-75 Standard.
Ti-3Al-2.5V (Grade 9) [Ti-3-2.5]
Medium strength, non-ageable Ti alloy offering highest strength and design allowable under the pressure vessel code with good weldability and cold fabricability for mildly reducing & oxidizing media.
Ti-3Al-2.5V-Pd (Grade 18) [Ti-3-2.5-Pd]
Pd-enhanced version of Ti-3Al-2.5V with equivalent physical and mechanical properties and fabricability offering elevated resistance to dilute reducing acids and crevice corrosion in hot halide (brine) media.
Ti-3Al-2.5V-Ru (Grade 28) [Ti-3-2.5-Ru]
Ru-enhanced version of Ti-3Al-2.5V with equivalent physical and mechanical properties and fabricability offering elevated resistance to dilute reducing acids and crevice corrosion in hot halide (brine) media. Approved for sour service use under the NACE MR-01-75 Standard.
Ti-5Al-2.5Sn (Grade 6) [Ti-5-2.5]
Weldable, non-ageable, high-strength alloy offering good high temperature stability, strength, oxidation and creep resistance.
Ti-5Al-2.5Sn ELI [Ti-5-2.5 ELI]
Extra low interstitial version of Ti-5Al-2.5Sn exhibiting an excellent combination of toughness and strength at cryogenic temperatures. Suited for cryogenic vessels for service as low as -255°C.
Highly creep-resistant, non-ageable, weldable, and high-strength Ti alloy for use up to 455°C exhibiting the lowest density and highest modulus of all commercial Ti alloys.
Weldable and high strength Ti alloy offering excellent strength, stability, and creep resistance to temperatures as high as 550°C.
A Guide to Commercial Titanium Alloys and Their Mill Product Forms
Ti-6Al-4V (Grade 5) [Ti-6-4]
Heat treatable, high-strength, most commercially available Ti alloy (the “workhorse” alloy for aerospace applications). Appropriate for use up to 400°C offering an excellent combination of high strength, toughness, and ductility along with good weldability and fabricability.
Ti-6Al-4V ELI (Grade 23) [Ti-6-4 ELI]
Extra low interstitial version of Ti-6Al-4V offering improved ductility and fracture toughness in air and saltwater environments along with excellent toughness, strength, and ductility in cryogenic service as low as -255°C. Typically used in a non-aged condition for maximum toughness.
Ti-6Al-4V-0.1Ru (Grade 29) [Ti-6-4-Ru]
Extra low interstitial Ru-containing version of Ti-6Al-4V offering improved fracture toughness in air, seawater, and brines, along with resistance to localized corrosion in sweet and sour acidic brines as high as 330°C. Approved for sour service use under the NACE MR-01-75 Standard.
High strength Ti alloy with good toughness and ductility used primarily for medical implants stemming from its excellent biocompatibility.
Heat-treatable and high-strength Ti alloy with higher strength and section hardness than Ti-6Al-4V but with lower toughness and ductility and limited weldability. Can be used in mill annealed or in aged (very high strength) conditions.
Heat-treatable, deeply-hardened, and very high strength Ti alloy with improved strength to temperatures as high as 450°C with limited weldability. Approved for sour service under the NACE MR-01-75 Standard.
Heat-treatable, high strength forging alloy with good strength and creep resistance to temperature as high as 400°C.
Heat-treatable and high strength Ti alloy with strength and fracture toughness-to-strength properties superior to those of Ti-6Al-4V. Excellent superplastic formability and thermal stability.
Heat-treatable and high strength Ti alloy with superior strength and exceptional hot and superplastic formability compared to Ti-6Al-4V, combined with good ductility and fatigue resistance.
Heat-treatable, deep section hardened and very high strength Ti alloy with superior strength and creep resistance over Ti-6Al-4V to temperatures as high as 400°C, and limited weldability.
Heat-treatable deeply hardened and very high strength Ti alloy possessing superior fatigue and strength/toughness combinations with exceptional hot-die forgeability but limited weldability.
Ti-3Al-8V-6Cr-4Zr-4Mo [Ti Beta-C™] (Grade 19)
A heat-treatable, deep section hardened and very high strength Ti alloy possessing good toughness/strength properties, low elastic modulus and elevated resistance to stress and localized corrosion in high temperatures and sweet and sour brines. Approved for sour service under the NACE MR-01-75 Standard.
Ti-3Al-8V-6Cr-4Zr-4Mo-0.05Pd [Ti Beta-C/Pd] (Grade 20)
A Pd-containing version of the Ti-38644 alloy (Beta-C/Pd) possessing equivalent physical/mechanical properties but with significantly enhanced resistance to stress and localized corrosion in high temperature brines.