汽车悬架系统用55SiCr弹簧钢丝带状组织

 为了研究中心偏析对弹簧钢组织性能的影响,通过金相显微镜、扫描电镜、电子探针等手段研究了55SiCr弹簧钢的元素偏析行为、带状组织及力学性能。结果表明,带状组织由合金元素偏析引起,其内部锰、铬和硅质量分数为非偏析带2倍以上,合金元素偏析引起带状组织,弹簧钢拉伸试样中裂纹起源于偏析带状组织,并沿垂直于带状组织方向扩展导致最终断裂,带状偏析是影响高强度弹簧钢力学性能的主要因素。

Bond structure of 55SiCr steel used for coil springs of automotive suspension system

In order to study the effect of central segregation on the microstructure and properties of spring steel,the elemental segregation behavior,banded structure and mechanical properties of 55SiCr spring steel were studied by means of metallographic microscope,scanning electron microscope and electron probe. The results show that the content of Mn,Cr and Si in the banded structure is more than 1 times higher than that in the matrix. The segregation of alloying elements causes the banded structure. Cracks in the tensile specimens of spring steel originate from the segregated banded structure and eventually fracture through the growth of the banded structure. The banded segregation is an important factor affecting the mechanical properties of high strength spring steel.