Embrittlement Tendency of 1Cr21Ni5Ti Duplex Stainless Steel Aged at Different Temperatures

Through the aging treatment of 1Cr21Ni5Ti duplex stainless steel at 400~600 ℃, the impact toughness and mechanical properties of 1Cr21Ni5Ti duplex stainless steel were tested. Combined with the observation of fracture morphology and metallographic structure, the aging embrittlement law of 1Cr21Ni5Ti duplex stainless steel at different temperatures was studied, and the measures to inhibit and alleviate embrittlement were put forward on the basis of the above research. The results indicate that the embrittlement tendency of 1Cr21Ni5Ti duplex stainless steel caused by aging at 550 ℃ is comparatively small, and the steel is more susceptible to embrittlement after aging at 450~500 ℃, which is attributed to the cleavage or quasi-cleavage fracture of ferrite phase due to its embrittlement. Meanwhile, higher Ti/C ratio increases the aging embrittlement tendency at 450~500 ℃. However, high Ti/C ratio can stabilize austenite phase, which can significantly reduce the aging embrittlement tendency at 600 ℃. It is also shown that increasing forging ratio can make austenite phase have sufficient deformation and make it uniformly distributed, which can effectively prevent the growth of brittle crack of ferrite phase and largely reduce the embrittlement tendency.