Filler-metal selection for FCAW depends on base-metal composition, cleanliness of base metal, thickness, a0d service. AWS specifications: A5.20, Specification for Carbon Steel Electrodes for Flux-cored Arc Welding, for low-carbon steel up to 0.15 C and mild steel 0.15 to 0.29 C; A5.29, Specification for Low Alley Electrodes for Flux-cored Arc Welding, for steel of higher carbon content and the low-alloy types; A5.22, Specification for Flux-cored Corrosion-Resisting Chromium and Chromium-Nickel Steel Electrodes, for stainless steels.Gas-Tungsten-Arc Welding (GTAW, TIG)GTAW rises an arc between a nonconsumable electrode and the work. It joins with or without filler metal. AWS A5.12 lists electrode types and sizes. All are tungsten, some with thoria, zirconia, ceria, or lanthana added. Thoria provides higher current-carrying capacity than prime tungsten with less contamination of the weld pool. Other benefits: better arc start, greater arc stability. Zirconiated electrodes perform well with alternating current: the arc is stable, the electrode retains a (tailed end during welding, and has current-carrying capacity of thoriated electrodes. Zirconiated electrodes resist contamination and minimize tungsten contamination of weld metal.

The application of microprocessor technology has long been expected to move out of the automotive world into heavy-duty engines and equipment, and now the first results of that technology are beginning to be felt in the industrial engine-powered equipment world."With electrically driven accessories, we have the ability to provide only the flow, pressure or power required to match actual operating conditions. By continuously adjusting to different operating modes, there are a number of control features and opportunities available," said David Orr, commercial manager of Caterpillar Inc.''s More Electric Initiative Program.

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