1Cr2Mn16N Steel Composition Control And Deformation Process Optimization

1Cr22Mn16N high nitrogen austenitic stainless steel has excellent corrosion resistance,wear resistance and low temperature mechanical properties,and has been widely used in the chemical,petroleum and nuclear industries.1Cr22Mn16N high nitrogen austenitic stainless steel with nitrogen instead of nickel,not only reduces the cost,but also has good overall mechanical properties.However,due to the addition of excessive nitrogen elements to increase its deformation resistance and easy to generate nitrogen porosity and other defects in the welding process,making it difficult to produce and shape in practice.Therefore,this topic for the above-mentioned problems of 1Cr22Mn16N composition control,and the study of its deformation process.In this thesis,the composition of 1Cr22Mn16N high-nitrogen austenitic stainless steel was firstly designed,determined its optimal composition,and regulated its organization and mechanical properties through heat treatment process optimization to obtain the best heat treatment process;then thermal deformation experiments were conducted using Gleeble 3800,and the effects of deformation temperature and strain rate on its rheological curve were analyzed.The effect of deformation temperature and strain rate on its rheological curve was analyzed,the instanton equation was established,and the thermal processing diagram was drawn.The effect of deformation temperature and deformation volume on the effect of plastic deformation connection was analyzed.In addition,the microstructure of the connection interface was characterized with the help of various characterization equipment such as optical microscope,scanning electron microscope and transmission electron microscope,and the effect of various parameters on the tissue evolution of the connection interface was analyzed to reveal the healing mechanism of the connection interface.The main findings of this thesis are as follows.1.Through pressurized induction melting,and by pressurized electroslag remelting and multidirectional forging can be prepared dense 1Cr22Mn16N high nitrogen austenitic stainless steel,the composition of the following（mass fraction,%）:Cr 21.3,Mn 14.4,Ni 1.78,C 0.014,Si 0.47,N 0.72,Fe balance.2.By analyzing the thermal deformation behavior at different deformation temperatures and deformation rates,it was found that the hot compression rheological stress of1Cr22Mn16N decreases with the increase of deformation temperature and decrease of strain rate during thermal deformation,and the discontinuous dynamic recrystallization occurring along the grain boundaries is the main softening mechanism.The apparent activation energy（Q）of 1Cr22Mn16N for high temperature deformation was calculated to be 350.1 k J/mol,and the Arrhenius instantonal relationship was established and verified to be accurate.The thermal processing diagrams showed that it is more suitable for processing at 1000-1100℃and 0.001-0.1 s^-1.3.By analyzing the plastic deformation connection interface of 1Cr22Mn16N at different deformation temperatures and deformation amounts,it is found that the interface bonding effect is better as the deformation amount and deformation temperature increase.When the temperature reaches 1200℃,the deformation amount of 40%,1Cr22Mn16N connection interface completely healed,its mechanical properties to the same level of the matrix.The interfacial bonding was achieved by the synergistic effect of continuous dynamic recrystallization and discontinuous dynamic recrystallization during the plastic deformation connection of high nitrogen austenitic stainless steel 1Cr22Mn16N.