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 Electrodes come 3 to 24 in. long, 0.01 to 0.25-in. diameter. Colored markings--bands or dots--indicate composition: pure tungsten, green; 1-percent thoriated, yellow; 2 percent thoriated. red; ceriated, orange; lanthanted, black.Filler metal GIAW does not usually requite addition of fillet metal, but filler is commonly added when base-metal thickness is greater than 1/8 in. Finer metal for low-carbon (to 0.15 C) and mild (0.15 m 0.29 C) steels are described in AWS A5.2; for carbon steel in A5.18; and for low-alloy akrcompressortank steels in A5.28 Flux. AWS specifications A5.17 and A5.23 describe fluxes for saw. AWS designation of fluxes precedes that of the wire when identifying a combination for a welding procedure. For example, the designation F7A2-EM12K indicates a flux (F) that will provide, akrcompressortank with a given wire designation, tensile strength of 70,000 Psi (7), in the as-welded condition (A), and impact properties of 20 ft lb at -20 F (2). A designation containing a P rather indicates the flux properties after postweld heat treatment. Welding-site conditions and welding-wire diameter govern efficiency and size of power supply required for a job. Select a 100-A unit that runs from single-phase 115-V input for low-duty-cycle welding of sheet to l/s in. thick, feeding wire to 0.030-in. diameter. Medium-duty power supplies, 150-200 A, normally take single-phase 220-V input to weld steel to 3/16, in. and 0.035-in. wire at low-duty cycles. For high-duty cycles, as in mechanized welding, select a 250-A machine, single or three-phase input at various voltages-these weld material to 1/2 in. thick with wire as large as 0.045-in. diameter. Taking three-phase input only and wire up to 1/6-in. diameter, 400-A units serve for mechanized continuous-welding applications. For pulsed GMAW, shops use inverter and transistor power sources, constant-current or constant-voltage, that offer independent setting of pulse parameters. They employ synergic controls preprogrammed for a range of wire-feed speeds-the operator sets only one dial, for average current. Hardfacing alloys contain as base elements typically iron, nickel, or cobalt, to which metallurgists add varying amounts of carbon, chromium, molybdenum, tungsten, silicon, manganese, vanadium, and boron. To raise hardness, the primary property for wear resistance, alloy designers add elements that either form hard constituents akrcompressortank (carbides, akrcompressortank borides, or Laves phase), or that strengthen the matrix by going into solid solution. Carbon content determines toughness akrcompressortank and abrasion resistance--as carbon rises, abrasion resistance increases and toughness drops. akrcompressortank Chromium forms carbides, increases corrosion resistance, and adds high-temperature strength. Tungsten, a potent carbide former, also boosts high temperature strength, as does cobalt. Tougheners include nickel and manganese. Boron forms hard wear-resistance borides. Searching for accessories for your air compressor? We offer the best selection of cheap air compressor accessories on the internet. Check out our website for great deales on all of our air compressor accessories!
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