【作者】 张振戎；

【导师】 傅万堂； 张文辉；

【作者基本信息】 燕山大学 ， 材料学， 2004， 硕士

【摘要】 本文用扫描电镜(SEM)、透射电镜(TEM)及X-射线衍射仪(XRD)等方法研究了几种硅、锰含量的Fe-0.8C合金在重度冷轧及退火后珠光体的显微组织变化与力学性能。结果表明： 对于等温退火后冷轧变形前的试样，伴随着锰和硅的添加，钢的抗拉强度和屈服强度提高，但总延伸率和均匀延伸率均变化不大。 由于硅、锰的添加，冷轧及退火后珠光体钢的抗拉强度与屈服强度得以大幅度提高(250～450MPa)，但它们对冷轧珠光体延性的影响却可以忽略。 相对于锰而言，硅的添加对于冷轧及退火后的珠光体钢延性的提高相当有效，尤其是当强度较高时，硅锰的复合添加对于重度冷轧及退火的珠光体钢拉伸性能的提高更有效。 对于冷轧态试样，如果在较低温度进行短时间退火，含硅或锰钢的拉伸强度和屈服强度与冷轧态的试样相比，几乎没有下降，但其延性却明显提高。 以硅、锰合金化的共析钢经90％冷轧及在450℃退火30～120s后，可获得最佳的拉伸性能。更多还原

【Abstract】 The changes of microstructures and mechanical properties of heavily cold -rolled and annealed pearlite were investigated by the use of SEM, TEM and XRD etc. in fully pearlitic Fe-0.8C alloys with different contents of Mn and Si. The effect of Mn and Si on the structures and mechanical properties were examined. The following results were obtained:For the as-transformed specimens, the tensile strength and yield strength are increased although the total elongation and uniform elongation hardly change with the addition of Mn or Si.As the rolling reduction increases, the strength of the cold-rolled specimens increases although the ductility remains nearly the same after the drastic decrease by 60% cold rolling. The addition of Mn and Si results in the increase in strength (250~450MPa) whereas their effect on the ductility is negligible.During the annealing at 923K after cold rolling, the growth of cementite is remarkably retarded and the strength is raised by the addition of Mn or Si. The addition of Si is effective for improving the ductility especially while the strength is higher. The combined addition of Mn and Si is more effective for improving the tensile properties of pearlitic alloys heavily cold-rolled and annealed at 650℃For the low temperature (450℃) -short time annealing, tensile strength and yield strength of alloys with added Mn and Si are little changed in comparison with the cold-rolled specimens, but the ductility is obviously improved. The optimal tensile properties in the alloys with Mn or Si are obtained after annealing at 450℃ for 30 to 120s.更多还原