循环变形对奥-贝球铁中的残留奥氏体转变及其对性能的影响

在一定的拉－压循环变形下，ＡＢ球铁中的残留奥氏体发生应变诱发转变，其转变量随应变量或循环次数的增加而增加。穆斯堡尔谱的研究表明，按其铁原子最近邻的碳原子的有无可将残留奥氏体分为两部分，且这两部分对变形诱发转变的稳定性不同。残留奥氏体应变诱发转变和强度增加，是导致ＡＢ球铁循环硬化和应变疲劳寿命下降的重要原因。

Transform of Residual Austenite in Austenite Bainite Nodular Cast Iron and Effect to Its Performance Under Cyclic Deformation Conditions

Under the certain cyclic pull press deformation condition,occurs strain induced transform in the residual austenite of A B nodular cast iron ,the transform magnitude shall be enlarged with increasing of strain amount or cyclic times.It is indicated by the Mossbauer spectrum study that having or having no carbon atoms nearest to the iron atoms can devide the residual austenite into two parts,these two parts have their own different stabilities to deformation induced transform.Strength increasing and induced transform by residual austenite strain are the major causes to lead to the cyclic hardening and to the strain fatigue life reduction of A B nodular cast iron.