Hi OBEWAN!
As Motgar also asked this question previously, I have to ask the same below... Also, what is the welding process as well as any other specifications being used to deposit these welds in question???
Do you have tubes - yes!! I mean tubes made of 308 Stainless steel material??? I emphasize the question in that manner not because I want to discredit you, or ridicule you OBEWAN ;) but, 308 is primarily used as filler metal - the standard for all the lower chromium-Nickel base metals...
The filler material for welding 302 & 304 grade stainless steel... This is the only reason why I ask you for clarification as to whether or not the base metal you are referring to is a 304 base metal as opposed to 308 stainless, and your company is actually working with both 304 as well as 316 grades of stainless steel instead, and why they do not prefer, or opt to switch to an "L" or, low carbon grade of these 2 base metals also.
http://www.ssina.com/publications/welding.htmlhttp://www.ssina.com/view_a_file/weldingbook.pdfThe other question I have to make better sense of your welding problem is, when is the nickel plating applied to the base metal, and can it be applied to the stainless metal after the welding operation is completed instead?
Here's another bunch of links that may or may not assist you further:
http://www.ssina.com/hintsandtips/index.html#4http://www.ssina.com/publications/ccss.htmlhttp://www.ssina.com/view_a_file/cleaning.pdfhttp://www.ssina.com/publications/design.htmlhttp://www.ssina.com/shopfabrication/knowledge.htmlWant to learn more about Stainless steels? Here you go:
http://www.ssina.com/training/index.htmlHere's an article, or two that may be of interest to you with respect to an alternative to 300 series Austenitic grades of Stainless steels.
http://www.inmotiononline.com.au/articles/1207-Alternative-stainless-steel-gradeshttp://www.worldstainless.org/NR/rdonlyres/16D7CBB1-1E5F-4338-9A5A-F53504A87667/3265/200seriesstainlesssteel.pdfhttp://www.assda.asn.au/index.php?Itemid=89&id=63&option=com_content&task=viewL & H Grades of Stainless Steels with respect to corrosion resistance:
http://www.corrosionist.com/L_H_grades_Stainless_Steels.htmHere's a nice stainless steel filler metal to base metal chart from Aufhauser:
http://www.brazing.com/products/Weld_Stainless/selection_chart.aspHere's a useful link to Stainless filler metal selection for various base metals, chemical composition, Flux cored stainless welding wire and shielding gases:
http://www.brazing.com/products/Weld_Stainless/Stainless steel pipe specifications:
http://www.indpipe.com/images/PDF/stainless_steel_pipe_specification.pdfHere'sa very thorough site regarding all sorts of Stainless steel info:
http://www.worldstainless.org/About+stainless/http://www.worldstainless.org/ISSF/Files/ISSF%20Book%20of%20New%20Applications%202009.pdfhttp://www.worldstainless.org/About+ISSF/Publications/http://www.worldstainless.org/SiteMap.htmEnjoy the reads!!! ;)
Respectfully,
Henry