AWS D10.7M-D10.7 pdf free download

AWS D10.7M-D10.7 pdf free download.Guide for the Gas Shielded Arc Welding of Aluminum and Aluminum Alloy Pipe.
4. Aluminum Pipe Alloys and Their Characteristics
Aluminum alloys have many characteristics which make them useful construction materials. Many of these properties, such as corrosion resistance, strength. light weight. protection of purity and color of the product transported. fracture toughness at cryogenic temperatures. and ease of fabrication are valuable in piping systems.
Many aluminum alloys are made in pipe form. The choice of the pipe alloy for a particular installation is made on the basis of the materials to he contained, the external exposure environment, and the service temperatures. For nominal chemical compositions. see Table 1. Alloy 3003-H 112, a nonheat-treatable alloy containing manganese, provides adequate strength for many applications, together with high corrosion resistance. Alloy 6063-T6. a heat treated aluminum-magnesium-silicon alloy, provides higher strength and equivalent corrosion resistance. Alloy 6061-T6 is similar in characteristics to 6063-T6. hut it has higher strength. In most environments, its corrosion resistance is equivalent to that of the 3(X)3 and 6063 alloys. Alloys 5086 and 5083. non- heat-treatable aluminum-magnesium-manganese alloys. provide superior as-welded strength and high fracture toughness at ambient and cryogenic temperatures.
It should be noted that the heat associated with welding reduces both tensile strength and design allowable values for most aluminum alloys. For example. for 606 1-T6 these values arc reduced about OflC third. For nonheattreatable alloys, the as-welded properties are normally those of the ‘SO” temper (i.e.. annealed) for that alloy. regardless of the starting temper.
Pipe in other alloys can be furnished for applications where high purity aluminum is required, where the design calls for higher strength, or where special corrosion resisting characteristics are desired. Alloys such as 1060. 5254, or 5652 may be used for high purity requirements. The 5254 and 5652 alloys are specially controlled purity versions of alloys 5154 and 5052. They belong to an important group of alloys which have magnesium as their principal alloying element.
Other alloys in this group are 5083, 5086. 5454. and 5456. These alloys are all nonheat-treatable hut have excellent as-welded strength and ductility. They generally exhibit high corrosion resistance: however, maximum service temperature requirements must be carefully investigated, since long time exposure to elevated tem- perature can adversely affect their corrosion resistance. Alloys 5052 and 5454 are recommended when sustained service temperatures are above 66°C [150°F]. Alloys 5083 and 5086 are used in marine applications. Alloy 5083 is favored for cryogenic applications. Clad versions of the standard alloys are sometimes used for corrosion resistance under special conditions. In the clad products, an integral coating (usually 10% of the pipe wall thickness) of an alloy selected is used to pro- vide cathodic protection to the core alloy. The presence of the cladding does not normally affect weldability. Combinations of alloys can be welded in most cases, and welding procedures should be based on core alloys. Annex A lists the diameters, wall thicknesses, and weights of aluminum pipe.5.1 Aluminum Oxide. Aluminum and oxygen have a strong affinity for each other, and aluminum oxide instantaneously begins to form on aluminum surfaces exposed to air. This oxide film is thin, transparent, tena- cious, and refractory with a melting temperature three times that of aluminum. An excessively thick oxide film that has become hydrated through exposure to moisture can cause welding difficulties and affect weld quality and should be removed by wire brushing before welding. The normal nonhydrated oxide film is removed progres- sively by the welding arc during the welding operation. AWS D10.7M-D10.7  pdf download.