Flux Core Arc Welding (FCAW) is a form of welding used in heavy equipment repair, structural steel erection, bridge construction, and ship and barge construction. Self-shielded flux core welding gives you the ability to use a wire feeding welding machine without the need for a regulated inert shielding gas. Flux core wire is a tube filled with flux; during the welding process this flux melts and creates a layer of slag on top of the weld, shielding it from the atmosphere while it cools.
Check the weld for porosity. Porosity is caused when small pockets of gas get caught in the weld making it appear as if it has holes in it. This can occur internally or on the surface weakening the structural integrity of your weld. Prevent porosity by preparing the surface of the metal you will be welding by cleaning away any rust, grease, paint, oil or dirt.
Check for worm tracking; this appears as lines across the surface of the weld. These lines are caused by excessive voltage for the wire feed setting you are using. Prevent worm tracking by using the manufacturer's recommended settings for the wire you are using.
Check for welding for undercutting. Undercut weakens the toe area of the weld and can cause cracking. To correct this problem, reduce your amperage, adjust your electrode angle and reduce your travel speed so that the weld metal completely fills the melted-out areas of the base metal you have been welding.
Check for proper penetration. To assure proper penetration clean the surface of the material you are welding and use the factory recommended voltage, and wire feed settings for the type of wire you are using. If your voltage setting is too high it can cause excessive penetration causing the weld to melt through the base metal and hang lower than it should. If your voltage is too low it can cause lack of penetration. Lack of penetration is the shallow fusion between the weld metal and the base metal.
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