Английский язык для инженеров сварочного производства. Гричин С.В - 54 стр.

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54
welding speeds are greater for GMAW than for SMAW. However, because
of the additional equipment, the process is less portable and versatile, but still
useful for industrial applications. The process can be applied to a wide
variety of metals, both ferrous and non-ferrous. A related process, flux-cored
arc welding (FCAW), uses similar equipment but uses wire consisting of a
steel electrode surrounding a powder fill material. This cored wire is more
expensive than the standard solid wire and can generate fumes and/or slag,
but it permits higher welding speed and greater metal penetration.
Submerged arc welding (SAW) is a high-productivity welding method
in which the arc is struck beneath a covering layer of flux. This increases arc
quality, since contaminants in the atmosphere are blocked by the flux. The
slag that forms on the weld generally comes off by itself, and combined with
the use of a continuous wire feed, the weld deposition rate is high. Working
conditions are much improved over other arc welding processes, since the
flux hides the arc and no smoke is produced. The process is commonly used
in industry, especially for large products.
3 Non-Consumable Electrode Methods
Gas tungsten arc welding (GTAW), or
tungsten inert gas (TIG) welding, is a
manual welding process that uses a non-
consumable electrode made of tungsten,
an inert or semi-inert gas mixture, and a
separate filler material. Especially useful
for welding thin materials, this method
is characterized by a stable arc and high
quality welds, but it requires significant
operator skill and can only be accomplished at relatively low speeds. It can
be used on nearly all weldable metals, though it is most often applied to
stainless steel and light metals. It is often used when quality welds are
extremely important, such as in bicycle, aircraft and naval applications. A
related process, plasma arc welding, also uses a tungsten electrode but uses
plasma gas to make the arc. The arc is more concentrated than the GTAW
arc, making transverse control more critical and thus generally restricting the
technique to a mechanized process. Because of its stable current, the method
can be used on a wider range of material thicknesses than can the GTAW
process, and furthermore, it is much faster. It can be applied to all of the same
materials as GTAW except magnesium, and automated welding of stainless
steel is one important application of the process. A variation of the process is

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