Gentlemen excuse me if I have interrupted. This is a Forum where everybody shares their Technical knowledge and experience so that it is useful to the concerned. Sometimes we may be wrong also and take it sportively without being offended. Argon + 2% N2 mixture is highly recommended for purging and shielding for the below purposes. 1. Nitrogen is an Austenite stabilizer and promotes Austenite formation in the duplex matrix. 2. It improves Pitting corrosion resistance. 3. The maximum solubility of Nitrogen in DSS A32205 is 0.2% and anything more than that will come out of the solution. 4. Nitrogen delays the formation of Intermetallic phases. "> 5. Nitrogen may be more efficient in aiding ASTM G48 corrosion test. But in ASTM A923, the weight loss is mainly due to Intermetallic Phases as higher PREN electrodes used such as Super duplex and Nickel base electrodes does not cause in weight loss due to pitting corrosion. I feel the main reason is higher alloy contents...
Materials selection, welding, forming, Heat treatment, corrossion, NDT