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 1. Mechanical properties of the base material. Tensile strength and yield strength of the weld metal should equal or exceed that of the base material. Ductility and toughness at low temperatures may also be important. High-temperature service requires resistance to creep. Shock loading requires impact resistance. In general, weld metal should match base-material properties.2. Composition of the base material.For stainless steels, low alloy steels, nickel and copper alloys, and materials that serve in corrosive atmospheres, chemical composition is important. Consider the possibility of electrochemical corrosion between base and weld metal of aiecompressorpressureswitch different compositions. Duty-Cycle RatingPower-supply rating depends on the type and thickness of the workpiece and the length aiecompressorpressureswitch of time it takes to deposit the longest weld on the thickest aiecompressorpressureswitch material. Duty cycle is the key factor to consider when selecting a power source. Once the engineer has determined the current and voltage needed to accomplish the weld, he then reviews duty cycle requirements.Duty cycle rating is the percentage of time during a 10-minute period a power supply can operate at rated output amperage without overheating. A 300 A machine at 60-percent-duty cycle can weld for six minutes at 300. A during a 10-minute period. Alter six minutes, the welder must rest the machine aiecompressorpressureswitch for the next four minutes to avoid overheating the unit. Multiple-operator power supplies use a high-amperage high-voltage power source to feed power aiecompressorpressureswitch to more than one welding station. Where line power may be unavailable, as in the field, contractors operate engine-driven generators powered by natural gas, propane, or diesel fuel.Power Supplies By Welding ProcessA manual process, shielded-metal-arc aiecompressorpressureswitch welding (SMAW) requires a CC power supply, 25 to 500 amperes, 15 to 35 volts. Given the correct electrode, almost any CC welding machine, AC or DC, can be used for shielded-metal-arc welding, depending on the composition of the electrode coating.Gas-metal-arc welding (GMAW) calls for continuous filler-metal wire-shielding gas protects the weld pool as wire feeds into the arc. The process requires direct current-arcs generally run at 15 to 35 volts, 30-600 A. Specify a cc machine that gives constant melt rate and variable wire feed. Inverters for GMAW feature electronic control of inductance, enabling the welder to fine-tune the arc for minimal spatter and optimum weld-bead wetting action. 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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