Study On Microstructure And Impact Toughness Of Super Duplex Stainless Steel 00Cr25Ni7Mo4N

Duplex stainless steel 00Cr25Ni7Mo4N covers a total of two parts,in particular,are ferrite and austenite,this feature gives its ideal physical and chemical properties.There is a problem of low temperature impact toughness of 00Cr25Ni7Mo4N steel produced in a factory in china.To solve the above problems,this paper stresses change material as the object of research and analysis,through standardized experiment,combining disease with type V impact test data,through optical microscope,scanning electron microscope and other advanced equipment of 00Cr25Ni7Mo4N steel structure and impact toughness were studied.The main work includes:1.to change the material to expand the processing of different temperatures,and then study the various types of refinement of the organization,to lay a good foundation for subsequent experiments.2.the results of the solid solution after the standardized test,so as to explore the impact of the reasons for the change in performance.3.all kinds of rolling process of the sample to carry out standardized test,so as to explore the impact of the performance of the reasons for the change.4.explore the relationship between precipitation and impact toughness.5.under the premise of the experiment,the phase diagram and the parameters of the material were well described by the TCW3.0 and TCFE3 database,and then the data were compared with the experimental data.The test showed that the corresponding dual phase steel phase ratio balance can significantly optimize the performance,greatly reduce the need for disease of the ductile brittle transition temperature of the phase morphology;the optimization of rolling process after that to adjust the corresponding materials,not only greatly optimize the impact toughness of 00Cr25Ni7Mo4N,at the same time let the material impact property at low temperature in low temperature environment can still reflect the ideal;the solution temperature normally at 1000～1020 ℃ interval,the material is easy to form the sigma phase,which leads to the embrittlement of steel.And a small number of sigma phase leads to a significant reduction in the low-temperature impact toughness of the material.Therefore,in the process of thermal processing should be avoided to maximize the temperature,while the good control of the cooling process after hot processing.