welding

Please see the following guide (What Every Engineer Should Know About Welding Procedures):

http://www.modernsteel.com/Uploads/Issues/May_1997/9705_03_welding.pdf

The short answer to your question is - following the WP.

Or in the absence of one / more generally please see the following literature (or the spec sheet of the consumable you are using):

http://content.lincolnelectric.com/pdfs/products/literature/c2410.pdf

http://content.lincolnelectric.com/pdfs/products/literature/c64000.pdf

http://content.lincolnelectric.com/pdfs/products/literature/c8100.pdf

thank u

Hello

try also this good sources:

http://www.millerwelds.com/resources/tech_tips/stick_tips/

http://www.millerwelds.com/resources/calculators/tig_amperage_calculator.php

S

corrosion protection

You can find Current and Voltage range of each filler wire and Electrode from manufacturer's data sheet or corresponding ASME Section-II Part-C SFA specification.

Even you can weld a test piece and measure the current and voltage.Test the specimen mechanically (Tensile,Charpy impact,bend,hardness etc. as per your requirement) after welding.If the test results meets your requirement,the recorded current and voltage is suitable for production welding.