Research On The Microstructure Characteristics And Wear Resistance And Fatigue Properties Of 00Cr40Ni55Al3Ti Bearing Alloy

The non-magnetic corrosion-resistant bearing alloy 00Cr40Ni55Al3Ti is a high-hardness non-magnetic alloy with Ti element added to the former Soviet Union40???-??alloy,Previous scholars mainly focused on heat treatment process and microstructure performance.There was no research on thermal processing,friction and wear and fatigue properties,and the research on strengthening mechanism was relatively lacking.This paper is based on the original,Using OM,SEM,TEM and XRD analysis methods and thermal simulation experiments,The microstructure evolution and high temperature plastic deformation behavior of 00Cr40Ni55Al3Ti alloy were studied,the effect of solution aging treatment on the microstructural characteristics and mechanical properties,precipitation strengthening mechanism and room temperature rotating bending fatigue properties.The wear resistance of the tested alloy was studied by friction and wear tests,and the wear mechanism of 00Cr40Ni55Al3Ti alloy under different friction conditions was preliminarily explored.?1?Microstructure evolution and high temperature plastic deformation behavior of00Cr40Ni55Al3Ti alloy were studied by hot compression test.The results show that the critical deformation of 00Cr40Ni55Al3Ti non-magnetic alloy is 10.8%.The deformation of the alloy is larger than the critical value.The dynamic recrystallization of austenite and nucleation and growth of spherical?-Cr phase occur in the alloy;When the deformation rate is 0.1s^-1,the alloy undergoes intermittent dynamic recrystallization.When the deformation rate is 5s-1,the nucleation and growth of spherical alpha-Cr phase at grain boundary cause inconsistency of deformation and softening fluctuation after peak stress;The activation energy of hot deformation is 397.077KJ/mol with 60%deformation.According to the thermal processing map,the suitable hot working area is determined:the deformation temperature is 1080¹100?,the deformation rate?is0.1⁰.35s^-1,the deformation temperature is 1120¹190?,and the deformation rate?is4.5¹0s^-1,which were in agreement with the test results of alloy forging.?2?The microstructure and mechanical properties of 00Cr40Ni55Al3Ti alloy after solution and aging treatment were studied.The results show that the lower the precipitation of spherical?-Cr phase is.?-Cr phase has the smallest size,the least precipitation and the lowest hardness at 1200?.When the solution temperature is 1200?and cooled at138?/s,the microstructures of 00Cr40Ni55Al3Ti alloy are spherical?-Cr phase,lamellar structure and non-lamellar structure.The hardness of lamellar structure is 703HV and that of non-lamellar structure is 249HV.The aging temperature is 600?,the aging time is 5h,6h and 7h,respectively.The microstructure is uniform distribution of lamellar structure and spherical?-Cr phase,The hardness of the lamellar structure is 691HV,706HV and712HV,respectively.The higher the percentage of microstructure area with higher hardness,the higher the Rockwell hardness of the alloy.?3?The precipitation strengthening mechanism of 00Cr40Ni55Al3Ti alloy during solution aging was calculated by strengthening theory,The results show that the strengthening increment is about 264 MPa,the displacement solid solution strengthening is49.54 MPa,the dislocation strengthening is 29.0 MPa,and the second phase??-Cr?is 9.46MPa.Aging strengthening increments are 940.82 MPa for lamellar structure,549.49 MPa for second phase??'?strengthening and coherent strain strengthening caused by?',334MPa for dislocation strengthening and 7.69 MPa for second phase??-Cr?.?4?The fatigue test of 00Cr40Ni55Al3Ti alloy after solution aging was carried out on QBWP-10000X rotary bending fatigue testing machine at room temperature.The results show that the ultimate strength of 00Cr40Ni55Al3Ti bearing alloy under rotational bending is 973 MPa.Among them,33.3%of the cracks occurred on the surface of TiN,53.3%on the hard spherical?-Cr phase and the remaining 13.4%caused cracking by Al₂O₃.?_h/?_w of rotating bending fatigue fracture specimens are all greater than 1,and the larger?_h/?_w,the shorter the fatigue life.?5?Fretting friction and wear tests of 00Cr40Ni55Al3Ti alloy were carried out by SRV-IV tester at room temperature,the friction coefficient of grease lubrication is about0.65 smaller than that of dry friction.The results show that and the fluctuation range of friction coefficient is smaller under different friction conditions.With the increase of sliding speed,the wear volume and the depth,length and width of wear spot increase gradually,the increase of wear volume is related to the increase of wear depth,length and width,The growth trend of grease lubrication is slower,and the volume and depth,length and width of wear spot are one order of magnitude lower than those of dry friction.