Effects of Solid Solution Treatment on Microstructure and Properties of 00Cr25Ni7Mo4N Duplex Stainless Steel

Hot rolled 00Cr25Ni7Mo4N duplex stainless steel was treated with solid solution at different temperatures and holding time.The effects of different solution treatments on the microstructure, corrosion resistance and mechanical properties of hot rolled 00Cr25Ni7Mo4N duplex stainless steel were studied by means of microstructure observation, tensile test, impact test and electrochemical test. The results show that 00Cr25Ni7Mo4N duplex stainless steel with solution at different temperatures is ferrite+austenite duplex microstructure.With the increase of solution temperature and solution time, the ferrite phase in 00Cr25Ni7Mo4N steel increases gradually, and the austenite phase decreases gradually. The ratio of two phases in 00Cr25Ni7Mo4N steel treated at 1060 ℃×20 min is the most close to 1∶1.The effect of solution holding time on the ratio of two phases in 00Cr25Ni7Mo4N duplex stainless steel is small.With the increase of solution temperature, the pitting potential of 00Cr25Ni7Mo4N steel increases first and then decreases.00Cr25Ni7Mo4N steel treated at 1060 ℃×20 min has the highest pitting potential of 1.089 V, which shows the best corrosion resistance. The tensile strength, yield strength, elongation and shock absorption energy of 00Cr25Ni7Mo4N duplex stainless steel are 852.3 MPa, 544.8 MPa, 39.2% and 328 J, respectively.