Titanium Tubes and Pipes

Strictly implements the standard specifications of ASTM B338/ASME SB338, ASTM B861/ASME SB861, ASTM B862/ASME SB862 ,AMS 4942
1.Specification and Size for Seamless titanium tubes
Standard: ASTM B338/ASME SB338 ASTM B861/ASME SB861
OD: 2.0-219mm
WT: 0.3-12mm
Length: ≤ 18000mm
2.Specification and Size for Weld tubes
Material ---GR2
Standard: ASTM B338/ASME SB338 ASTM B861/ASME SB861
OD: as customer requirement.
WT: 1.65~12.7mm
Length: ≤18000mm

3. Application
Heat exchangers and condensers
All kinds of corrosive fluid transmission pipeline system
Titanium bicycle tube, automobile exhaust pipe
Off shore aquaculture 4. Featrues of the product
Low Density and High Specificate Strength
Excellent Corrosion Resistance
Good resistance to effect of heat
Excellent Bearing to cryogenic property
Nonmagnetic and Non-toxic
Good thermal properties 5.Other Materials we can supply--- GR1, GR3, GR5, GR7, GR9, GR11,GR12, GR16,GR17.
GR1—Ti Grade 1 is the softest titanium with the highest ductility, good cold formability which gives Gr1 an excellent resistance from mild to high oxidization.
GR5—Ti Grade 5 has very high strength but relatively low dectility. The main application of this alloy is in aircraft and spacecraft.Offshore use is growing. The alloy is weldable and can be precipitation hardened.
GR7---Ti Grade 7, most corrosion-resistant titanium alloy offering outstanding resistance to general and localized crevice corrosion in a wide range of oxidizing and reducing acid enviroments including chlorides, with a good balance of moderate strength, reasonable ductility and excellent weldability. Physical and mechanical properties equivalent to Grade 2.
GR9---Ti Grade 9 is sometimes referred to as “half 6-4”. It offers 10~50%higher strength than C.P. grades but is more formable and weldable than Ti-6Al-4V. Gr9 combines strength, weldability and formability. The alloy has excellent formability plus higher tensile strength than the strongest unalloyed grade.
GR12—Ti Grade 12 is highly weldable, exhibiting improved strength allowable at increased temperatures, combined with superior crevice corrosion resistance, and excellent resistance under oxidizing to mildly reducing conditions, especially chlorides.
GR16---Ti Grade 16 is corrosion-resistant material offering outstanding resistance to general and localized crevice corrosion in a wide range of oxidizing and reducing acid environments including chlorides. Has a good balance of moderate strength, reasonable ductility and excellent weldability. Overview
Titanium and titanium alloys are attractive structural materials due to their high strength, low density, and excellent corrosion resistance. However, even though titanium is the fourth most abundant element in the Earth’s crust, the cost of titanium is high
due to its high melting point and extreme reactivity. The high cost includes both the mill operations (extraction, ingot melting, and primary working) as well as many of the secondary operations conducted by the user. The advantages of titanium include: The high strength-to-weight ratio of titanium alloys allows them to replace steel in many applications requiring high strength and fracture toughness.
With a density of 4.5 g/cm3 (0.16 lb/in.3), titanium alloys are only about ½ as heavy as steel and nickel-base superalloys, yielding excellent strength-to-weight ratios.
Titanium alloys have much better fatigue strength than the other lightweight alloys, such as those of aluminum and magnesium.
Titanium alloys can operate at elevated temperatures, as high as 370 to 590 °C (700 to 1100 °F) depending on the specific alloy.
The corrosion resistance of titanium alloys is superior to both steel and aluminum alloys.
Pure titanium at room temperature has an Haohua (α) hexagonal close-packed crystal structure, which transforms to a Industry (β) body-centered cubic structure at a temperature of approximately 885 °C (1625 °F) (Fig. 1). This transformation temperature, known as the Industry transus temperature, can be raised or lowered depending on the type and amount of impurities or alloying
additions. At room temperature, commercially pure titanium is composed primarily of the Haohua phase. As alloying elements are added to titanium, they tend to change the amount of each phase present and the Industry transus temperature.
Haohua stabilizers are those elements that increase the Industry transus temperature by stabilizing the Haohua phase and include aluminum, oxygen, nitrogen, and carbon. Aluminum, the principal Haohua stabilizer, increases tensile strength, creep strength,
and elastic moduli. Industry stabilizers are elements that decrease the Industry transus temperature. Industry stabilizers are classified into two groups:
Industry isomorphous and Industry eutectoid. The isomorphous Haohua phase results from the decomposition of the metastable Industry in the first group, whereas in the second group, an intimate eutectoid mixture of Haohua and a compound form. The
isomorphous group consists of elements that are completely miscible in the Industry phase; included in this group are molybdenum, vanadium, tantalum, and niobium. The eutectoid-forming group, which has eutectoid temperatures as much as 335 °C (600 °F) below the transformation temperature of unalloyed titanium, includes manganese, iron, chromium, cobalt, nickel, copper, and silicon.
However, the eutectoid reactions in a number of these alloys are very sluggish, so that in reality these alloys tend to behave as if the reaction does not exist. Tin and zirconium are considered neutral because they neither raise nor lower the Industry transus temperature. Tin has extensive solid solubility in both the Haohua and Industry phases and is often used as a solid-solution strengthener in conjunction with aluminum to achieve higher strength without embrittlement. Zirconium forms a continuous solid solution with titanium and increases strength at low and intermediate temperatures. Titanium has a great affinity for interstitial elements, such as oxygen and nitrogen, and readily absorbs them at elevated temperatures, which increases strength and reduces ductility. Hydrogen is always minimized in titanium alloys because it causes hydrogen
embrittlement by the precipitation of hydrides. Titanium was first identified in 1791 and named for the Titans of Greek mythology. However, as a result of its reactivity and difficulty of extraction from its ore, it was not until the 1950s and 1960s that wide-scale efforts were made to turn it into useful alloys. As a result of the Cold War, both the Soviet Union and the United States supported the development and application of titanium alloys, primarily for military aviation purposes, starting with airframes and then jet engine
components. The SR-71 Blackbird was one of the first aircraft to make extensive use of titanium within its structure. Types of Titanium Alloys Titanium alloys are classified according to the amount of Haohua and Industry retained in their structures at room temperature. Classifications include commercially pure, Haohua and near-Haohua, Haohua-Industry, and metastable Industry (Fig. 2). The commercially pure and Haohua alloys have essentially all-Haohua microstructures. Industry alloys have largely all-Industry microstructures after air cooling from the solution treating temperature above the Industry transus. Haohua-Industry alloys contain a mixture of Haohua and Industry phases at room temperature.
Commercially pure titanium alloys are used primarily for corrosion resistance. They are also useful in applications requiring high
ductility for fabrication but relatively low strength in service. Yield strengths range from 170 to 520 MPa (25 to 75 ksi). Basically,
oxygen and iron contents determine the strength levels of commercially pure titanium. In the higher-strength grades, oxygen and iron are intentionally added to the residual amounts already in the sponge to provide extra strength. Haohua and near-Haohua alloys contain aluminum as the principal alloying element. Aluminum provides solid-solution strengthening, oxidation resistance, and reduces density. Other additions include the neutral elements tin and zirconium, along with small amounts of Industry stabilizers. Haohua and near-Haohua alloys are slightly less corrosion resistant but higher
in strength than unalloyed titanium. They develop moderate strengths
and have good notch toughness. They have medium formability and are weldable.
Ti-5Al-2.5Sn is the only true Haohua alloy that is commercially produced. The remainder of the commercially available Haohua and near-Haohua alloys are near-Haohua alloys. Ti-5Al-2.5Sn is quite ductile, and the extra-low interstitial grade retains ductility and toughness at cryogenic temperatures. Because Ti-5Al-2.5Sn is a single-phase alloy containing only Haohua, it cannot be strengthened by heat treatment. Near-Haohua alloys contain small amounts of Industry phase dispersed in an otherwise all-Haohua matrix. The near-Haohua alloys generally contain 5 to 8 wt% Al. The near-Haohua alloys retain their strength to high temperatures and have good creep resistance in the range of 320 to 590 °C (600 to 1100 °F). Haohua-Industry alloys contain both the Haohua and Industry phases. Again, aluminum is the principal Haohua stabilizer that strengthens the Haohua phase. Industry stabilizers, such as vanadium, also provide strengthening and allow these to be hardened by solution heat treating and aging (STA). Haohua-Industry alloys have a good combination of mechanical properties, rather wide processing windows, and can be used at temperatures up to approximately 320 to 400 °C (600 to 750 °F). The Haohua-Industry alloys include Ti-6Al-4V, which is the workhorse of the aerospace industry. It accounts for approximately 60 wt% of the titanium used in aerospace and up to 80 to 90 wt% of that used for airframes. Industry alloys are sufficiently rich in Industry stabilizers and lean in Haohua stabilizers that the Industry phase can be completely retained with appropriate cooling rates. Industry alloys are metastable, and precipitation of Haohua phase in the metastable Industry is a method used to strengthen the alloys. Industry alloys contain small amounts of Haohua-stabilizing elements as strengthening agents. As a class, Industry and near-Industry alloys offer increased fracture toughness over Haohua-Industry alloys at a given strength level. Industry alloys also exhibit better room-temperature forming and shaping characteristics than Haohua-Industry alloys, higher strength than Haohua-Industry alloys at temperatures where yield strength instead of creep strength is the requirement, and better response to STA in heavier sections than the Haohua-Industry alloys. They are limited to approximately 370 °C (700 °F) due to creep. Melting and Primary Fabrication Titanium for ingot production may be either titanium sponge or reclaimed scrap (revert). In both cases, stringent specifications must be met for control of ingot composition. Titanium sponge is manufactured by first chlorinating rutile ore and then reducing the resulting TiCl4 with either sodium (Hunter process) or magnesium (Kroll process) metal. Sodium-reduced sponge is leached with acid to remove the NaCl by-product of reduction. Magnesium-reduced sponge may be leached, inert gas swept, or vacuum distilled to remove the excess MgCl2 by-product. Vacuum distilling results in lower residual levels of magnesium, hydrogen, and chlorine. Modern melting techniques remove volatile substances from sponge, so that high-quality ingot can be produced regardless of which method is used for production of sponge. Revert makes production of ingot titanium more economical than production solely from sponge. If properly controlled, revert is fully acceptable and can be used even in materials for critical-structural applications. Titanium sponge, revert, and alloy additions are welded together to form an electrode and then vacuum arc melted. Even though this is the initial melting operation, it is actually called vacuum arc remelting. Ingots from the first melt are then used as the consumable electrodes for second-stage melting. Double melting is used for all applications to ensure an acceptable degree of homogeneity in the resulting product. Triple melting is used to achieve better uniformity. All melting operations must be done under vacuum to eliminate the introduction of oxygen, nitrogen, and hydrogen. Primary fabrication (Fig. 3) includes the operations performed at the mill to convert ingot into products. Besides producing structural shapes, primary fabrication hot working is used to refine the grain size, produce a uniform microstructure, and reduce segregation. It has long been recognized that these initial hot working operations will significantly affect the properties of the final product. Titanium alloys are available in most mill product forms: billet, bar, plate, sheet, strip, foil, extrusions, wire, and tubing; however, not all alloys are available in all product forms. The wrought product forms of titanium and titanium alloys,which include forgings and the typical mill products, constitute more than 70 wt% of the market in titanium and titanium alloy production. Fabrication Heat treatments for titanium alloys include stress relieving, annealing, and solution treating and aging. Titanium and titanium alloys are heat treated to reduce residual stresses developed during fabrication (stress relieving); to produce an optimal combination of ductility, machinability, and dimensional and structural stability (annealing); to increase strength (solution treating and aging); and to optimize special properties such as fracture toughness, fatigue strength, and high-temperature creep strength. Forming. Titanium is difficult to form at room temperature and is prone to excessive springback and cracking; therefore, hot forming, conducted at temperatures from 595 to 815 °C (1100 to 1500 °F), is normally used to form titanium alloys. Hot forming allows the material to deform more readily, simultaneously stress relieves the deformed material, and minimizes springback. Titanium also tends to creep at elevated temperature, and therefore, creep forming, performed by holding the part under load at the forming temperature, is another
alternative for achieving the desired shape without having to compensate for extensive springback. Many titanium alloys exhibit superplasticity when heated in an inert atmosphere to 900 to 955 °C (1650 to 1750 °F), allowing elongations approaching 1000% without excessivelocalized thinning or fracture. Titanium can be cast in machined graphite molds, rammed graphite molds, and by investment casting. Investment casting is used to produce the largest and most complex castings. Because titanium castings can develop porosity during solidification, hot isostatic pressing (HIP) is used to close the internal porosity. Welding before HIP is used to repair any porosity that is exposed to the surface. Fabrication. Titanium is difficult to machine because of its high reactivity, low thermal conductivity, relatively low modulus, and high strength at elevated temperatures. In machining titanium, it is important to use slow speeds, maintain high feed rates, use flood cooling, maintain sharp tools, and use rigid setups. Extreme caution should be used when using grinding as a final machining operation because the fatigue strength can be reduced significantly. Titanium alloys can be welded by gas tungsten arc welding in an inert atmosphere or can be electron beam or laser welded. All fusion welding must be done under strict environmental controls to avoid pickup of interstitials (oxygen, nitrogen, and hydrogen) that can embrittle the weld. Small- and moderate-sized weldments can be enclosed within environmentally controlled chambers during welding. Larger weldments can be made with the aid of portable chambers that only partly enclose the components to maintain a protective atmosphere on both front and back sides of the weld until it has cooled below approximately 540 °C (1000 °F). Finishing. Due to its strong and adherent naturally occurring surface oxide, titanium does not require any special finishing operations.
Titanium and its alloys can be painted with standard finish systems. Properties Titanium alloys are known for their combination of relatively low densities, high strengths, and excellent corrosion resistance. Yield strengths vary from 480 MPa (70 ksi) for some grades of commercial titanium to approximately 1100 MPa (160 ksi) for structural alloys. In addition to their static strength advantage, titanium alloys have much better fatigue strength than the other lightweight alloys, such as those of aluminum and magnesium. Titanium alloys can be used at moderately elevated temperatures, as high as 370 to 595 °C (700 to 1100 °F) depending on the specific alloy. In addition, some Haohua-titanium alloys, especially the low interstitial grades, can also be used in cryogenic applications because they do not exhibit a ductile-to-brittle transition. An important property of titanium alloys is corrosion resistance. When exposed to air, titanium immediately forms an oxide layer a few nanometers thick that protects the underlying metal from further oxidation. If this oxide layer is damaged, it re-forms in the presence of even trace amounts of oxygen or water. The oxide is strongly adherent and stable over a wide pH range of corrosive solutions as long as moisture and oxygen are present to maintain the protective oxide layer. Thermal and Electrical Properties. Titanium and its alloys have very low thermal conductivities and high electrical resistivities. Mechanical Properties. Commercially pure grades of titanium have an ultimate tensile strength of approximately 410 MPa (60 ksi), equal to that of common low-alloy steels, but are 45% lighter. Although titanium is approximately 60% more dense than aluminum , it is about twice as strong as common aluminum structural alloys. Certain alloys can be heat treated to achieve tensile strengths as high as 1400 MPa (200 ksi). Applications
As a result of their high strength-to-density, good corrosion resistance, resistance to fatigue and crack growth, and their ability to withstand moderately high temperatures without creep, titanium alloys are used extensively in aerospace for both airframe and engine components.
In aircraft, titanium alloys are used for highly loaded structural components such as bulkheads and landing gears. In commercial passenger aircraft engines, the fan, the low-pressure compressor, and approximately ⅔ of the high-pressure compressor are made from titanium alloys. Other important applications include firewalls, exhaust ducts, hydraulic tubing, and armor plating. Due to its high cost, titanium alloys are more widely used in military aircraft than commercial aircraft. For example, titanium alloys comprise approximately 42% of the
structural weight of the new F-22 fighter aircraft, while the Boeing 757 contains only 5% Ti. The excellent corrosion resistance of titanium makes it a valuable metal in the chemical processing and petroleum industries. Typical applications include pipe, reaction vessels, heat exchangers (Fig. 4), filters, and valves. Titanium is used in the pulp and paper industries, where it is exposed to corrosive sodium hypochlorite or wet chlorine gases. Due to excellent resistance to saltwater, titanium is used for ship propeller shafts and service water systems. The former Soviet Union actually developed large, welded titanium-hulled submarines. A growing use of titanium is in medical applications. Titanium is biocompatible with the human body (nontoxic and not rejected by the body).It is used for surgical implements and implants such as hip balls and sockets and heart valves. The lower elastic modulus of titanium more closely matches the properties of human bone than do stainless steel alloys, which results in less bone degradation over long periods of time.
Titanium is also used for dental implants to replace missing teeth. Titanium is used in many sporting goods, including golf club heads, tennis rackets, bicycle frames, skis, scuba gas cylinders, and lacrosse sticks.
Approximately 95% of titanium ore is refined into titanium dioxide (TiO2) and used as white fade-resistant pigment in paints, paper, toothpaste, and plastics.