研究了感应加热淬火工艺参数对轮毂轴承法兰内圈淬火硬化层和组织的影响。结果表明,随着感应加热总能量的提升,淬硬区宏观轮廓逐渐增大,淬硬层深度加深;内圈淬硬区表层及次表层正常组织为细针马氏体+板条马氏体,淬火加热总能量过高会导...研究了感应加热淬火工艺参数对轮毂轴承法兰内圈淬火硬化层和组织的影响。结果表明,随着感应加热总能量的提升,淬硬区宏观轮廓逐渐增大,淬硬层深度加深;内圈淬硬区表层及次表层正常组织为细针马氏体+板条马氏体,淬火加热总能量过高会导致表层过热而形成粗针马氏体,甚至过烧;过渡区正常组织为细针马氏体及少量的铁素体+屈氏体,淬火加热总能量过低会导致过渡区形成大量的屈氏体组织,同时残留铁素体量也会增多。感应淬火加热功率180 k W,加热时间5.4 s为最佳的工艺参数。展开更多
To clarify the work hardening discrepancy effect on the strengthening of laminated metals,we designed two laminated Cu/Cu4Zn and Cu/Cu32Zn samples with different layer thicknesses.Cu/Cu4Zn has larger work hardening di...To clarify the work hardening discrepancy effect on the strengthening of laminated metals,we designed two laminated Cu/Cu4Zn and Cu/Cu32Zn samples with different layer thicknesses.Cu/Cu4Zn has larger work hardening discrepancy between two constituent layers relative to Cu/Cu32Zn,but the yield strengths of two Cu Zn constituents are comparable.Uniaxial tensile results suggest Cu/Cu4Zn with larger work hardening discrepancy exhibits a significant strengthening at early deformation stage while Cu/Cu32Zn possesses a better ductility.The underlying mechanisms for the strengthening effect are attributed to more geometrically necessary dislocations accumulated at interfaces and severer strain localization due to the larger work hardening discrepancy.展开更多
To investigate the relation between material＇s cychc plastic behaviour and fatigue crack growth, a new model is proposed. The model incorporated the two intrinsic properties of material＇ s cyclic plastic and crack ...To investigate the relation between material＇s cychc plastic behaviour and fatigue crack growth, a new model is proposed. The model incorporated the two intrinsic properties of material＇ s cyclic plastic and crack tip＇ s deformation dislocation to interpret fatigue crack threshold. The relation between material＇ s cyclic hardening parameters （cyclic hardening amplitude and cyclic hardening rate） and fatigue threshold is studied. Fatigue threshold is determined based on the dislocation-free zone （DFZ） model, the theory of cohesive zone and the cyclic deformation behaviour. The results show that fatigue threshold increases with the decrease of the amplitude of cyclic hardening and is independent of cyclic hardening rate, but fatigue crack growth rate increases with the increase of cyclic hardening rate.展开更多
文摘研究了感应加热淬火工艺参数对轮毂轴承法兰内圈淬火硬化层和组织的影响。结果表明,随着感应加热总能量的提升,淬硬区宏观轮廓逐渐增大,淬硬层深度加深;内圈淬硬区表层及次表层正常组织为细针马氏体+板条马氏体,淬火加热总能量过高会导致表层过热而形成粗针马氏体,甚至过烧;过渡区正常组织为细针马氏体及少量的铁素体+屈氏体,淬火加热总能量过低会导致过渡区形成大量的屈氏体组织,同时残留铁素体量也会增多。感应淬火加热功率180 k W,加热时间5.4 s为最佳的工艺参数。
基金financial support by the National Natural Science Foundation of China(Nos.U1608257 and 51931010)the Key Research Program of Frontier Science and International Partnership Program(No.GJHZ2029)+3 种基金CAS,Liao Ning Revitalization Talents Program(No.XLYC1802026)financial support by the National Natural Science Foundatiosn of China(No.52001312)the Project Funded by China Postdoctoral Science Foundation(Nos.BX20190336 and 2019M661150)the Open Research Fund from the State Key Laboratory of Rolling and Automation,Northeastern University(No.2018RALKFKT002)。
文摘To clarify the work hardening discrepancy effect on the strengthening of laminated metals,we designed two laminated Cu/Cu4Zn and Cu/Cu32Zn samples with different layer thicknesses.Cu/Cu4Zn has larger work hardening discrepancy between two constituent layers relative to Cu/Cu32Zn,but the yield strengths of two Cu Zn constituents are comparable.Uniaxial tensile results suggest Cu/Cu4Zn with larger work hardening discrepancy exhibits a significant strengthening at early deformation stage while Cu/Cu32Zn possesses a better ductility.The underlying mechanisms for the strengthening effect are attributed to more geometrically necessary dislocations accumulated at interfaces and severer strain localization due to the larger work hardening discrepancy.
基金Sponsored by the Fundamental Research Foundation of Harbin Engineering University(Grant No.HEUFT07007)
文摘To investigate the relation between material＇s cychc plastic behaviour and fatigue crack growth, a new model is proposed. The model incorporated the two intrinsic properties of material＇ s cyclic plastic and crack tip＇ s deformation dislocation to interpret fatigue crack threshold. The relation between material＇ s cyclic hardening parameters （cyclic hardening amplitude and cyclic hardening rate） and fatigue threshold is studied. Fatigue threshold is determined based on the dislocation-free zone （DFZ） model, the theory of cohesive zone and the cyclic deformation behaviour. The results show that fatigue threshold increases with the decrease of the amplitude of cyclic hardening and is independent of cyclic hardening rate, but fatigue crack growth rate increases with the increase of cyclic hardening rate.
