Soham Impex SI-TIG-300, Руководство по эксплуатации

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Note! This section being general welding technique guide is for reference only. Specific
functions of your machine please refer to previous chapters.

TIG welding technique
Heat Input
The DC power source uses what is known as DC (direct current) in which the main electrical
component known as electrons flow in only one direction from the negative pole (terminal) to the
positive pole (terminal). In the DC electrical circuit there is an electrical principle at work which should
always be taken into account when using any DC circuit. With a DC circuit 70% of the energy (heat) is
always on the positive side. This needs to be understood because it determines what terminal the TIG
torch will be connected to (this rule applies to all the other forms of DC welding as well).
TIG ARC
DC TIG welding is a process in which an arc is struck between a TUNGSTEN electrode and the metal
work piece. The weld area is shielded by an inert gas flow to prevent contamination of the tungsten,
molten pool and weld area.
When the TIG arc is struck the inert gas is ionized and superheated changing it‘s molecular
structure
which converts it into a plasma stream. This plasma stream flowing between the tungsten and the work
piece is the TIG arc and can be as hot as 9000K+. It is a very pure and concentrated arc which
provides the controlled melting of most metals into a weld pool. TIG welding offers the user the
greatest amount of flexibility to weld the widest range of material and thicknes s and types. DC TIG
welding is also the cleanest weld with no sparks or spatter.
13. BASIC WELDING TECHNIQUE