Investigation of microstructure and property of Cr21 type low-nickel duplex stainless steel

摘要

Two sorts of Cr21 type duplex stainless steel (DSS)containing 1.2% Ni and 0% Ni were designed and investigated.The results showed that yield stress of Cr21 DSS reached 450 MPa,being twice of 304 austenite stainless steel.Impact energy of nickel-free DSS (LND1)at room temperature was about 89 J (sub-sized).At -20°C,impact energy was reduced to 24J.Note that for DSS containing 1.2% Ni (LND2),impact energy at 20°C was as high as 92 J.This indicated that Ni was the critical element for increasing impact property at low temperature.The paper also revealed that over 1000°C,impact energy decreased with increase annealing temperature due to volume of austenite phase deceased.Meantime,refinement of austenite phase would increase impact energy of Cr21 type DSS.