Stainless steel pipe welded pipe welding why use nitrogen

The role of nitrogen in stainless steel welded pipes is mainly reflected in three aspects: the structure, mechanical properties and corrosion resistance of stainless steel. Nitrogen is a very strong element that forms and stabilizes austenite and expands the austenite phase. It can replace part of nickel in stainless steel, reduce ferrite content and make austenite more stable. Precipitation of harmful intermetallic phases and martensitic transformation are prevented even under cold conditions.

The effect of nitrogen on the mechanical properties of stainless steel: nitrogen significantly increases the strength without reducing the ductility and toughness of stainless steel materials; nitrogen stainless steel can improve creep resistance, fatigue resistance, wear resistance and yield strength. As an element that improves corrosion resistance, it can also form nitrogen gas in NH 4 + in pores, eliminate H + generation, suppress pH value, thereby inhibiting the occurrence of pitting corrosion and dissolution rate in metal pores, and improve localized corrosion.