Rtech Tig200, Руководство по эксплуатации

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3.4 Stainless Steel
Is a high quality process ideally suited for
welding of stainless steels, particularly thin sheet
up to about 5mm thick where weld integrity
and good surface finish are critical.The process
has a high degree of controllability resulting
in clean, smooth, high quality welds with good
penetration and strength with very low defect
rates.
Standard TIG equipment is suitable and stainless
steels are TIG welded using DCEN polarity.
A thoriated tungsten electrode is normally
used but health concerns have promoted use
of ceriated or lanthanated instead.The filler
rod used depends on the type of stainless being
welded but, in general, is matching for austenitic
grades, enriched in nickel for duplex grades,
and may be matching or an austenitic type for
ferritic and martensitic grades.
Shielding gas is conventionally pure argon, but
other gases are available to provide specific
properties and these include argon-hydrogen,
argon-helium mixtures, argon-helium-hydrogen,
and argon-nitrogen mixtures.
When welding pipes an inert gas purge is
required inside the pipe to prevent oxidation
on the underside of the weld. Gas purging may
also be used to protect the root side of butt
welds in plate or sheet materials too.