龙龙 2007-11-4 23:03
Plasma Arc Welding (PAW) 简介
[b]Plasma Arc Welding[/b] (PAW) uses electrodes and ionized gases to generate an extremely hot plasma jet aimed at the weld area. The higher energy concentration is useful for deeper and narrower welds and increased welding speed. Plasma is a gas which is heated to an extremely high temperature and ionized so that it becomes electrically conductive. Similar to GTAW (TIG), the plasma arc welding process uses this plasma to transfer an electric arc to a work piece. The metal to be welded is melted by the intense heat of the arc and fuses together. Plasma gases are normally argon. The torch also uses a secondary gas, argon, argon/hydrogen or helium which assists in shielding the molten weld puddle thus minimizing oxidation of the weld.y]z*}^f
The plasma welding process was introduced to the welding industry as a method of bringing better control to the arc welding process in lower current ranges. $h9c!b,e t.W
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p[b]lasma welding[/b] derives its unique operating characteristics from the torch design. As in TIG welding, the arc is formed between the end of a small diameter tungsten electrode and the workpiece. However, in the plasma torch, the electrode is positioned behind a fine bore copper nozzle with a small opening at the tip. A pilot arc is initiated between the torch electrode and nozzle tip. This arc is then transferred to the metal to be welded. Plasma is present in all arcs. By forcing the plasma gas and arc through a constricted orifice, the torch delivers a high concentration of heat to a small area. With high performance welding equipment, the plasma process produces exceptionally high quality welds. This results in a higher arc temperature and a more concentrated heat pattern than exists in TIG welding.
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Modern Plasma equipment and welding techniques have improved to where these processes can address applications which were formerly performed by more expensive processes such as laser or electron beam welding. Precision plasma arc welding systems are now the optimum solution. This has helped to reduce or eliminate the formerly high capital costs, running costs and service costs associated with the manufacturing processes using laser and electron beam.P!i.z oGt"p
Plasma arc welding is adaptable to both manual and automatic operations, and can be used to produce either continuous or intermittent welds. The plasma process can gently, yet consistently, start an arc to the tip of wires or other small components and make repeatable welds with very short weld time periods.
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Today, plasma retains the original advantages it brought to industry by providing an advanced level of control and accuracy to produce high quality welds in miniature or precision applications and to provide long electrode life for high production requirements.
龙龙 2007-11-4 23:03
[b]Plasma Arc Welding[/b]9A1_\M f B
[list][*]Plasma Arc Welding (PAW) uses electrodes and ionized gases to generate an extremely hot plasma jet aimed at the weld area.[*]The higher energy concentration is useful for deeper and narrower welds and increased welding speed[/list][b]Plasma Arc Cutting[/b]
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[list][*]Plasma arc cutting can increase the speed and efficiency of both sheet and plate metal cutting operations. Manufacturers have discovered its benefits.[*]Plasma cutters are used in place of traditional sawing, drilling, machining, punching, and cutting.[*]The high-temperature plasma arc cuts through a wide variety of metals at high speeds.[*]Although plasma arc cutting can cut most metals at thickness of up to 4 to 6 inches, it provides the greatest economical advantages, speed, and quality on carbon steels under 1 inch thick, and on aluminum and stainless steels under 3 inches thick.[*]Plasma arc cutting has gained approval in both hand-held and automated cutting operations[*]Impressive results are achieved in automated systems.[*]Advances in computer numerical controls (CNC), robots, and other automation techniques have offered manufacturers higher cutting speeds achieved through plasma arc cutting.[*]Improved torch designs and more efficient power supplies have made plasma arc cutting increasingly popular.[*]New areas of technology in plasma arc cutting systems include non-transferred arc plasma, which allows plastics and other nonconductive materials to be cut.[*]Research on cutting plastics is continuing and at least one commercial process is currently available.[/list]