|Aluminum plays an important role in the manufacture of every conceivable type of equipment ranging from railroad cars, trucks and buildings, to cooking utensils. In most cases, welding is used in the fabrication of these aluminum products.
Aluminum weighs only about one-third as much as other commonly used metals; it has a high strength-to-weight ratio, is highly resistant to corrosion, possesses great electrical conductivity, and permits unusual ease of fabrication.
What is STAINLESS STEEL?
|Stainless steel is a family of iron based alloys that must contain at least 10.5% CHROMIUM (Cr). The presence of chromium creates an invisible surface film that resists oxidation and makes the material "passive" or corrosion resistant (i.e. "stainless"). This family can be simply and logically grouped into five (5) branches. Each of these branches has specific properties and a basic grade or "type." In addition, further alloy modifications can be made to "tailored" the chemical composition to meet the needs of different corrosion conditions, temperature ranges, strength requirements, or to improve weldability, machinability, work hardening and formability.|
| Cast iron is an iron-based material with a high percentage of carbon. The five types of cast iron are gray, white, malleable, alloy, and nodular.
Gray cast iron is used a great deal for machine castings. It can readily be identified by the dark gray, porous structure when the piece is fractured. Gray cast iron can be welded with comparative ease.
White cast iron possesses what is known as combined carbon. The fractured piece of white cast iron will disclose a fine, silvery white, silky, crystalline formation. Although white cast iron can be welded, welding is not recommended for this metal.
Malleable cast iron is usually white cast iron which has been subjected to a long annealing process. A fractured piece of malleable cast iron will indicate a white rim and a dark center. Malleable cast iron can be welded; however you must be sure that the metal is not heated above critical temperature. Heating beyond this point reverts the metal back to its original characteristics of white cast iron.
Alloy cast iron can be arc welded, but greater precautions must be taken in the preheating and post-weld heat treatment to prevent the destruction of the alloying elements.
Nodular iron sometimes called ductile iron has the ductility of malleable iron, the corrosion resistance of alloy cast iron and tensile strength greater than gray cast iron. Nodular can be arc welded, providing adequate preheat and post-weld heat treatments are used; otherwise some of the original properties are lost.
Gas Tungsten Arc Welding (GTAW) is frequently referred to as TIG welding. TIG welding is a commonly used high quality welding process. TIG welding has become a popular choice of welding processes when high quality, precision welding is required.
In TIG welding an arc is formed between a non consumable tungsten electrode and the metal being welded. Gas is fed through the torch to shield the electrode and molten weld pool. If filler wire is used, it is added to the weld pool separately.
|Gas Metal Arc Welding (GMAW) is frequently referred to as MIG welding. MIG welding is a commonly used high deposition rate welding process. Wire is continuously fed from a spool. MIG welding is therefore referred to as a semiautomatic welding process. Repair: railing, pipe, trailers, aluminum restaurant equipment|