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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 aircomprrssoraccessories base-material properties.2. Composition of aircomprrssoraccessories the base material.For stainless steels, aircomprrssoraccessories low alloy steels, nickel and copper aircomprrssoraccessories alloys, and materials that serve in corrosive atmospheres, chemical composition is important. Consider the possibility of electrochemical corrosion aircomprrssoraccessories between base and weld metal of different compositions. For flux-cored-arc welding, shops use CV or CC types, aircomprrssoraccessories 300 to 1,500 A, 25 to 50 V, rated 60- to 100-percent-duty cycle. CV types are more popular because wire-feed speed, set before welding, controls welding current. Cc types require a variable-speed or voltage-sensing wire feeder.Gas-tungsten-arc welding (GTAW) requires a constant-current (AC or DC) power supply with a steep volt-amp curve to minimize current change for variation in voltage aircomprrssoraccessories or arc length. They come rated to 1,500 A, 10 to 75 V, at 40- to 100-percent-duty cycle. Most GTAW power supplies come equipped with high-frequency circuitry for arc initiation and stabilization, gas valves, and cooling-water valves for high-current welding. High-frequency arc start is useful when the maximum open-circuit voltage allowed aircomprrssoraccessories by NEMA standards, 80 to 100 V, will not establish and maintain a stable arc. Duty-Cycle RatingPower-supply rating depends on the type and thickness of the workpiece and the length of time it takes to deposit the longest weld on the thickest material. Duty cycle is the key factor to consider when selecting a power source. Once the engineer has determined aircomprrssoraccessories 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 aircomprrssoraccessories a 10-minute period. Alter six minutes, the welder must rest the machine for the next four minutes to avoid overheating the unit. 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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