Performance characteristics of duplex stainless steel

(1) Molybdenum containing duplex stainless steel has good resistance to chloride stress corrosion under low stress. Generally, 18-8 austenitic stainless steel is prone to stress corrosion fracture in neutral chloride solutions above 60 ° C. In industrial media containing trace amounts of chloride and hydrogen sulfide, equipment such as heat exchangers and evaporators made of this type of stainless steel tends to experience stress corrosion fracture, while duplex stainless steel has good resistance.
(2) Molybdenum containing duplex stainless steel has good resistance to pitting corrosion. When having the same equivalent value of pitting resistance (PRE=Cr%+3.3Mo%+16N%), the critical pitting potential of duplex stainless steel is similar to that of austenitic stainless steel. The pitting corrosion resistance of duplex stainless steel and austenitic stainless steel is equivalent to AISI 316L. The resistance to pitting and crevice corrosion of high chromium duplex stainless steel containing 25% Cr, especially nitrogen, exceeds that of AISI 316L.
(3) Has good corrosion fatigue resistance and wear corrosion performance. Suitable for producing power equipment such as pumps and valves under certain corrosive media conditions.
(4) Good comprehensive mechanical performance. It has high strength and fatigue strength, with a yield strength twice that of 18-8 austenitic stainless steel. The elongation of the solid solution state reaches 25%, and the toughness value AK (V-shaped groove) is above 100J.
(5) Good weldability, low tendency for hot cracking, generally does not require preheating before welding, and does not require heat treatment after welding. It can be welded with 18-8 austenitic stainless steel or carbon steel and other dissimilar materials.