冷铁和冒口对ZL702A合金组织和力学性能的影响

Effects of Chills and Riser on Microstructure and Mechanical Properties of ZL702A Alloy

利用金相显微镜和室温拉伸试验研究了冷铁和冒口对ZL702A合金组织和力学性能的影响。结果表明:优选呋喃树脂砂的目数为50/100,配方为树脂含量1.0%,固化剂0.4%。在一定范围内,冷铁越厚,组织越致密,综合力学性能越高。在实际的大型复杂结构铸件的生产过程中,应依据所需的性能、组织和冷速布置冷铁,在保证铸件顺序凝固的前提下尽可能增大冷铁厚度。根部尺寸大的冒口样品的二次枝晶臂间距小,综合力学性能高。冒口位置在铸锭中间时,合金的二次枝晶臂间距较小,合金的综合力学性能较高。

In this paper,the effects of chills and riser on the microstructure and mechanical properties of the ZL702A alloy were studied by metallographic microscope and tensile test at room temperature.The results showed that the mesh number of furan resin sand was 50/100,the resin content was 1.0%,and the curing agent was 0.4%.Within limits,the thicker the chill was,the denser the microstructure was,and the higher the comprehensive mechanical properties were.In the actual production process of large and complex structural castings,the chill shall be arranged according to the required properties,microstructure and cooling rates,and the chill thickness shall be increased as much as possible on the premise of ensuring the sequential solidification of castings.The riser samples with large root size had small secondary dendrite arm spacing and high comprehensive mechanical properties.When the riser was in the middle of the ingot,the secondary dendrite arm spacing of the alloy was small,and the comprehensive mechanical properties of the alloy were high.