Effects of Heat Treatment Processes on Microstructure of 22Cr Duplex Stainless Steel

Effects of heat treatment processes including solution treatment,solution and ageing treatment,on the microstructure and intermetallic phase of 22Cr duplex stainless steel were investigated.The microstructure of the rolled steel sheets annealed at a temperature lower than 1 150 ℃ is regular strip structure of α phase and γ phase.The γ phase become isometric when temperature is up to 1 150 ℃.The content of α and γ phases has a linear correlation with the solution temperature in the range of 950-1 150 ℃.The intermetallic precipitate came from α phase in the ageing treatment at 850 ℃ after the solution treatment at 1 050 ℃.The content of intermetallic phase increased with the time of ageing.The intermetallic phase in the ageing treatment at 475 ℃ is not found under the optical microscope.