1, the proportion: the proportion of titanium alloy in 4.51 or so, is usually 57% of stainless steel, Titanium Tube so it is easier to distinguish from the feel.
2, color: titanium metal color is gray, color texture is different from stainless steel, aluminum. As the titanium alloy is more difficult to polish and color, so usually the surface of titanium alloy products are mechanical polishing or scrub, Titanium Tube only a few high-grade titanium alloy products, local polishing mirror, and mechanical polishing and matte surface color is titanium alloy unique gray or deep gray.
3. Strength: Titanium alloy strength is higher than the general stainless steel and aluminum alloy, can reach 2 times the stainless steel.
TA2 is pure titanium, TC4 is titanium, non-professional users more difficult to find the real TC4 in the market, because TA2 and TC4 from the surface of the basic distinction, the density of TC4 although the heavy, but this can not be used as a standard, but pure Titanium tube and TC4 tube processing technology is not the same, pure titanium are through the tube, TC4 can not wear, only mechanical processing. Simple visual identification method can refer to the inner wall of titanium tube, mechanical processing is not smooth, is the possibility of TC4 or other titanium alloy, Titanium Tube and smooth is the possibility of pure titanium, but this method is not necessarily accurate.
Now the pipe industry developed, not through the 304 seamless steel process and quality is actually very good, such as outside 32 within 26 (wall thickness 3mm) or outside 35 within 28 (wall thickness 3.5mm) 304 seamless steel pipe, On the wall thickness of the same circumstances, the smaller the smaller the diameter can withstand high pressure) as long as there is no obvious deformation or damage inside and outside, the critical point can withstand about 20 mpa pressure, but this is the critical point, it may at any time Fried! (Mpa: normal air is a standard atmospheric pressure ≈ 0.1mpa, that is 1mpa ≈ 10 standard atmospheric pressure, Titanium Tube that is 1 cubic 1mpa pressure release to the standard atmospheric pressure can fill 10 cubic feet of space and so on, for example, your Titanium tube pressure of 20mpa, the release of the air can be filled about 200 times the hands of your titanium tube, about 200 times the pressure can be compressed sloppy).
Titanium tube has a high strength, good plastic toughness and corrosion resistance, in the aerospace, shipbuilding, chemical applications more and more widely. To better use titanium tube, you must grasp the weldability. This paper mainly elaborates the welding technology of titanium tube, which provides a useful reference for the welding of titanium tube in the future.
Titanium tube welding is the use of inert gas on the welding area for effective protection of TiG welding process. As the titanium material has a special physical and chemical properties, and thus the welding process and other metals there is a big difference. Welding must ensure that: (1) welding area of metal above 250 ℃ from the active gas N, 0, H and harmful impurities such as C, Fe, Mn and other pollution. (2) can not form coarse grain structure. (3) can not produce a large welding residual stress and residual deformation. Therefore, the welding process to be a reasonable process, in strict accordance with the process of quality management standards, Titanium Tube the implementation of the entire process of quality control. So that people, machines, materials, France, the factors are in a well-controlled state, which in a reasonable period of time to ensure the quality of titanium tube welding.
Materials, equipment and tools
1, titanium tube and accessories: should have the factory's factory certificate and quality certificate.
2, welding materials
2.1 welding wire: titanium wire, specifications for the φ2.0, φ3.0. The welding wire should be cleaned and degreased by the cleaning method of the groove before use. When welding, the end of the welding wire should be removed to 10 ~ 20mm long.
2.2 welding wire in the use of materials before the re-inspection, Titanium Tube check the factory certificate and quality certificate; wire surface should be clean, no oxidation color, no cracks, from the skin, scar and slag and other defects.
2.3 argon: industrial grade pure argon, the purity shall not be less than 99.98%, water content of less than 50Mg / L argon before use in the bottle on the factory certificate to verify the purity of hydrogen indicators, and then Check the valve valve for leak or failure.
2.4 tungsten: choose φ2.0 ~ φ3.0 mm cerium tungsten pole.
3, welding equipment
3.1 welding machine: the use of DC TiG (WS) welder. The welding machine should ensure excellent working characteristics and adjustment characteristics, and is equipped with a good ammeter and voltmeter.
3.2 torch: the use of QS a 75 ° / 500 water-cooled TiG (WS) torch. Welding torch should have a simple structure, lightweight and durable, gun body tight, good insulation, air flow stability, Titanium Tube folder tungsten holding solid, suitable for a variety of location welding characteristics.
3.3 argon pipe; semi-rigid plastic pipe, should not use rubber hose and other absorbent materials. Should be used in particular, not with the delivery of other gas tube string with each other. Argon tube should not be too long, so as not to pressure drop caused by excessive airflow instability, generally not more than 30m.
3.4 welding fixture: austenitic stainless steel or copper tube Kalan, locking bolts and other groups on the titanium tube and accessories. Should ensure that the titanium tube and accessories have a certain clamping force to ensure that the axis of the same, evenly appropriate gap.
3.5 auxiliary equipment and tools: argon protective cover, polisher, special file, Titanium Tube stainless steel wire brush, and so on.