AWS A5.13/A5.13M:2010 pdf free download

AWS A5.13/A5.13M:2010 pdf free download.Specification for Surfacing Electrodes for Shielded Metal Arc Welding.
A6.1 Role of Hydrogen in Surfacing. Hydrogen can be detrimental to surfacing deposits. The effect varies widely from one alloy type to another. Hydrogen can be detrimental to weld ductility and also result in hydrogen-assisted cracking in the weld metal or HAZ. In general, hydrogen’s detrimental effect is the most pronounced for martensitic types, with austenitic types being the least affected. Other factors influencing hydrogen’s effect include carbon and alloy contents plus in- service welding variables.
In welding there are many sources for hydrogen contamination. Coating moisture is one of the most important ones. Most electrodes arc manufactured and packaged to control moisture. When received, consideration must be given to proper storage to prevent moisture pick-up. During use, improper regard to welding procedure and environmental variables can result in spalling or “hydrogen-induced’ (underbead) cracking.
A6.2 Low equipment cost, great versatility, and general convenience make manual shielded metal arc welding very popular. The welding machine, which is essentially a power conversion device, is usually the main item of equipment needed. It may be a motor-generator, transformer, transformer-rectifier combination, or fuel-operated engine combined with a generator. The arc power may be either direct or alternating current. The filler metal is in the form of covered electrodes. (Bare electrode arc welding is a rarity today, though it is feasible with austenitic manganese steel electrodes.) Welding can be done in almost any location and is practicable for a variety of work, ranging from very small to quite large. For some applications, it is the only feasible method: and, for many others (especially where continuous methods do not offer significant benefits), it is the economical choice.
The operation is under the observation and control of the welder, who can easily cover irregular areas and often correct for adverse conditions. It is also helpful if the welder exercises judgment in other matters, such as holding the arc power down to minimize cracking; keeping a short arc and avoiding excessive puddling to minimize the loss of expensive alloying elements in the filler metal; minimizing dilution with base metal; and restricting hydrogen pickup. This process is used extensively for hardfacing. buttering, buildup, and cladding.
Surfacing of carbon and low-alloy steels, high-alloy steels, and many nonferrous metals may be done with the shielded metal arc process. Base metal thicknesses may range from 1/4 in [6 mm] to 18 in [45() mml. The surfacing metals employed include low- and high-alloy steels, the stainless steels, nickel-base alloys, cobalt-base alloys, and copper-base alloys.AWS A5.13/A5.13M:2010 pdf free download.