【摘要】 利用OM、SEM、XRD、洛氏硬度计、维氏硬度计及材料试验机，研究了Si、Cu与P含量和等温淬火工艺对球墨铸铁组织与力学性能的影响。结果表明，等温淬火组织均为奥铁体+球状石墨。随着等温温度的升高，针状铁素体尺寸增大，残留奥氏体含量增加。当等温温度为300℃时，球墨铸铁的综合力学性能最佳。在相同Si含量下，Cu和P元素的添加可以增加基体中石墨球的数量，提升石墨球圆整度，减小等温淬火球墨铸铁的针状铁素体尺寸，提升等温淬火球墨铸铁的强塑性。经300℃等温淬火，Si含量为1.1%时，添加0.6%Cu的球墨铸铁获得最高屈服强度，可达1363 MPa。更多还原

【Abstract】 Effects of Si, Cu, and P contents and isothermal quenching process on the microstructure and mechanical properties of nodular cast iron were studied by using OM, SEM, XRD, Rockwell hardness tester, Vickers hardness tester, and material testing machine. The results indicate that the microstructure after isothermal quenching is composed of ausferrite and spherical graphite. As the isothermal temperature increases, the size of acicular ferrite increases and the retained austenite content increases. The comprehensive mechanical properties of nodular cast iron are optimal when the isothermal temperature is 300 ℃. Under the same Si content, the addition of Cu and P elements can increase the number of graphite nodules in the substrate, improve the roundness of graphite nodules, reduce the size of acicular ferrite in isothermal quenched nodular cast iron, and enhance the strength and plasticity of isothermal quenched nodular cast iron. Specifically, when the Si content is 1.1%, the addition of 0.6%Cu achieves the yield strength of 1363 MPa of the nodular cast iron isothermal quenched at 300 ℃.更多还原