Sparkling Justsun 2023-12-06 20:58:31

供应Titanium GR12 Seamless Pipe
Product Description

Type: Titanium GR12 Seamless Pipe
Material: Titanium Grade 12 (UNS R53400/Ti-CODE 12/Ti-0.3Mo-0.8Ni)
Size:

Outside diameter: 6″ (DN150/168.3mm)
Thickness: SCH80S(10.97mm)
Standard: ASME B861

Corrosion Resistance
Titanium alloys are usually used in Australia for their excellent corrosion resistance, especially to chloride solutions. The small additions of nickel and molybdenum to grade 12 titanium give a more corrosion resistant metal than the commercial purity grade 2 alloy, with a marked increase in strength. The overall corrosion resistance of this grade is not as good as the palladium alloyed lean grade 7, except for resistance to crevice corrosion in hot chloride solutions. Titanium has excellent resistance to general corrosion, with loss rates of less than 0.04mm/year being typical.

Fabrication

Titanium alloy grade 12 is forged conventionally, within the narrow temperature range 815 – 900°C. Titanium and titanium alloys are generally more difficult to forge than both aluminium and alloy steels, due to their high strain rate sensitivity and rapid increase of strength with falling temperature. Hot forging lees a thick, hard outer layer of titanium oxide on the surface. This layer is called “Alpha Case” and is usually removed by pickling in a mixture of nitric and hydrofluoric acids. As supplied, titanium alloys are usually annealed and pickled, and can be readily cold formed in conventional machines using standard methods. In cold forming the “alpha case” does not form and further pickling is not needed, except to remove any carbon steel embedded in the surface, which can cause pitting corrosion.

Machinability
Titanium alloy grade 12 is readily machinable by conventional methods. Like stainless steel, titanium has a low thermal conductivity and heat dissipation is inhibited, so copious amounts of coolant should be used. Sharp carbide tools are used. Deep, continuous cuts are best.

Weldability

Titanium alloy grade 12 is readily weldable by GMAW (MIG) and GTAW (TIG) processes. Preheat or post weld heat treatment are not needed. The area to be welded must be CLEAN, free from all grease and shop dirt, including marking pencil marks. A trailing gas shield is used in addition to the normal welding torch gas shield, to prevent hey oxidation during cooling. Matching filler metal to AWS specification ERTi-12 is used. The gas shield must be low in hydrogen, oxygen and nitrogen, all of which readily dissolve in titanium and cause embrittlement.

Heat Treatment
Titanium Grade 12 is normally supplied in the annealed condition. After fabrication, stress relief at 480 – 595°C, air cooled, may be required to improve dimensional stability.