What Is Titanium Grade 11
Titanium Grade 11 is a low-strength commercially pure titanium grade with 0.12 to 0.25 percent palladium added for enhanced corrosion resistance. It is essentially Grade 1 titanium with the palladium addition, so it retains the optimum ductility and cold formability of Grade 1 while gaining much better resistance to crevice corrosion and to reducing acid environments. The palladium acts as a cathodic alloying element that shifts the corrosion potential into the passive range, which is why Grade 11 resists attack in environments where unalloyed titanium would corrode, such as hot chloride solutions and reducing acids.
Extreme Environment Service
Grade 11 titanium tubes are used in extreme environments where the medium combines chlorides, reducing conditions and elevated temperature. Typical services include gas and process tubing in sour and chloride-laden applications, heat exchanger tubing in seawater cooling circuits, and components in chemical plants handling hydrochloric acid and other reducing media. The tubes resist pitting, crevice corrosion and stress corrosion cracking, and they maintain their integrity where carbon steel, copper alloys and even standard stainless steels fail within months.
Available Specifications
Grade 11 titanium tubes are supplied to the main titanium tube specifications. ASTM B861 covers seamless titanium and titanium alloy pipe, with outside diameters from about 4 mm to 219 mm and wall thicknesses of 0.5 to 20 mm, and ASTM B862 covers welded pipe, available up to large diameters. The schedules follow the standard pipe series from SCH5 to SCH160, and the conditions include hot-finished, annealed, cold-drawn, polished, annealed and pickled, and bright annealed. Lengths are supplied as single random, double random or cut lengths, with plain, beveled or threaded ends as specified.
Testing and Certification
Value-added testing confirms the quality of Grade 11 tubes: hardness testing, flattening and flaring tests, pitting resistance testing, spectro chemical analysis, micro and macro examination, intergranular corrosion testing, mechanical testing including tensile, and positive material identification by PMI. The material test certificates are issued in accordance with EN 10204 3.1 and 3.2, and the tubes are marked with standard, grade, OD, thickness, length and heat number for full traceability.
Selecting Grade 11 vs Other Grades
Grade 11 is selected where maximum corrosion resistance in reducing and crevice conditions is needed together with the formability of Grade 1. Where higher strength is required in the same environment, Grade 7, the palladium-bearing equivalent of Grade 2, is the choice, and Grade 16 and 17 offer palladium additions at lower levels for intermediate resistance. The selection is driven by the service medium, temperature and mechanical loading, and the specification should be confirmed against the application before ordering.
Frequently Asked Questions
What is Grade 11 titanium? Low-strength commercially pure titanium with 0.12 to 0.25 percent palladium for enhanced corrosion resistance.
What standards cover Grade 11 tubes? ASTM B861 for seamless pipe and ASTM B862 for welded pipe.
Why does palladium improve corrosion resistance? It acts as a cathodic alloying element, shifting the corrosion potential into the passive range.
What tests are performed on Grade 11 tubes? Hardness, flattening, flaring, pitting, chemical, metallographic, corrosion, tensile and PMI tests.
What is the difference between Grade 11 and Grade 7? Grade 7 is the palladium-bearing equivalent of Grade 2, offering higher strength with similar corrosion resistance.
