Welding of Titanium.
Main methods of welding titanium - arc welding in inert gas, submerged, electroslag and electron beam.
Arc welding in inert gases, titanium and its alloys can be carried out or ittrirovannym lantanirovannym nonconsumable tungsten electrode and consumable electrode argon is applied only to the premium GOST 10157-73 or helium of high purity. Welding is performed with the use of elongated nozzles at nozzle (up to 500 mm) with gas from the back side through a special lining, as well as in chambers with controlled atmosphere. Titan small thickness (up to 4 mm) tungsten arc welded to the conventional apparatus for automatic argon- non-consumable electrode arc welding. Filler rod is fed only with metal thickness of 1.5 mm. It is also possible manual welding with direct current straight polarity. No feed filler rod bond strength is the strength of the base metal. When submitting his rod heated surface adsorbs a certain amount of atmospheric gases, which leads to a decrease in ductility of the weld metal by 40-50%. When the thickness of the metal used more than 4 mm groove V, and X-shaped ryumkoobraznuyu. To increase the depth of penetration during welding tungsten electrode is used, the paste flux AN-TA, which is applied a thin layer on the surface of the edges. They allow no cutting edges sva-regarded metal thickness up to 12 mm smaller than the conventional methods, welding currents. This technology reduces the deformation of welded structures and reduces the porosity of the joints, and promotes a partial refinement of the weld metal. When welding, submerged arc, with no cutting edge, you can also connect the metals increased thickness. When welding consumable electrode for the two runs (both sides) can be welded without the metal bevel edge thickness of 36 mm. As the inert gas argon and helium are used (Table 106). When welding in two passes in the joints obtained by argon relatively narrow (Fig. 164, a), and helium - a wide-Kimi (Fig. 164, c), which is associated with the physical properties of protective gases for welding in helium requires a a high voltage arc. Welding lead to a direct current of reverse polarity. Mechanical properties of weld metal and the strength of the connection in general depend on the type of titanium grade filler wire and can be communicated to the relevant parameters of the base metal. For automatic welding under this scheme uses the modernized machine DT-500 M, DT-1000-24, for welding fillet welds - Automatic ACS-MI and semi-urban village type 2. When upgrading standard equipment (for welding steels) focuses on increasing the feed rate wire (instead of the usual 50-600 m / h it was adjusted to 2500-3000 m / h) and create the conditions for full protection of the metal during welding. Power Supply - with a rigid characteristic. From the standpoint of reducing the consumption of scarce and expensive materials and welding performance is important to the welding of titanium to narrow the gap - cutting a slit that runs non-consumable tungsten or consumable electrode. In the first case, collect the sheets with a gap of a - 6 h, 12 mm diameter tungsten electrode, d = 3-4 mm diameter filler wire 1.5-2 mm, the welding current 200-300 A, argon flow rate 12.9 l / minutes after the burner and 2-3 l / min from the reverse side. If you are using MIG wire diameter of 1.6-2 mm at the same argon flow rate, strength of the welding current 360-420 A and voltage of 32-36 V. In submerged arc welding and electroslag welding using oxygen-free fluxes (AN-AN-T1 and T2 ), the main components of which - fluoride (GaF2, Na2F) and chloride (KC1, NaCl). To reduce the risk of getting the hydrogen in the weld metal is required that the moisture content in the flux did not exceed 0.05%. Titanium welded under flux in the standard equipment on the DC reverse polarity. This method is economically efficient in combined metal thickness greater than 6-8 mm, although the weld metal and thinner. Strength and ductility of welded joints are not lower than the base metal. In electroslag welding to protect the slag bath and the cooling of the metal is carried out blowing argon through special channels in the sliders at the rate of 5.12 l / min for the metal thickness 30-120 mm.
See also:
Welding of Titanium Metal
Welding of Aluminum
Titanium
Welding Magnesium
Welding of Titanium
Copper
Welding of Copper
Refractory Metals
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