|
|
 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 aircomoressorreplacementpressureswitches the thickest 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 aircomoressorreplacementpressureswitches 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 for the next four minutes to avoid overheating the unit. Weld wire. SAW uses electrodes of continuous wire, solid or flux- or metal-cored. Selection depends on base-metal composition and thickness, flux, joint design, and cleanliness. AWS specifications A5. 17 and A5.23 detail filler materials for SAW of carbon and low-alloy steels; aircomoressorreplacementpressureswitches and aircomoressorreplacementpressureswitches A5.9 and A5.1, filler metals weld corrosion-resisting stainless steels and nickel alloys, respectively.Hardfacing ElectrodesHardfacing welds a wear-resistant material to a substrate-base material that is commonly mild, alloy, or stainless steel. Hardfacings can be deposited manually using aircomoressorreplacementpressureswitches SMAW electrodes; semiautomaticaly using solid wire and self shielded flux cored electrodes; or automatically by submerged-arc welding. The method chosen depends on the size and accessibility of the area to be surfaced. 5. Joint design and material thickness. Some electrodes create an arc that penetrates deeply, performing well on thick sections with narrow grooves or no bevel. Poor fit-up calls for electrodes that can bridge wide gaps.6. Efficiency. Meeting all other conditions, engineers select the electrode that gives highest deposition rate. For heavy-section joints, use powder-metal-addition fillers.Designating electrodes for carbon and low-alloy steels, following the prefix E'', to signify a SMAW electrode, come two or three digits to indicate minimum tensile strength in 1,000 PSI units; a digit indicating usable current and electrode-coating type; and, in some cases, a hyphen followed by a letter and number suffix to denote weld metal composition. Example: E7010-A1 is a SMAW electrode (E), of 70,000-psi tensile strength (70), for use in all welding positions (1), having a high-cellulose-sodium coating tin use with DCEP (0). -A1 indicates a particular composition listed in the A5 specification. A-1 suffix, as in 7018-1, indicates high impact toughness at a temperature lower than specified for a standard E7018 electrode. 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!
|