ZL114A基座铸件铸造工艺设计与力学性能研究

Study on Casting Process Design and Mechanical Properties of ZL114A Base Casting

应用于某战术导弹构件的ZL114A基座铸件选用开放式浇注系统与米字型横浇道结构设计,在低压充型下通过增设冷铁实现了自下而上的平稳充型与自上而下的顺序凝固,选择14 h的落砂开箱时间,基座铸件最大尺寸正偏差仅为0.7 mm,最大尺寸负偏差仅为-0.8 mm。经二次固溶T6热处理与低温稳定化后,合金材料的抗拉强度、屈服强度、伸长率与布氏硬度分别为340.7 MPa、265.7 MPa、7.8%与HBS94,晶界处的Mg_2Si强化相与球状Si相平均尺寸更加细小,分布更为均匀弥散,断裂机制为韧窝断裂与沿晶断裂。

With the use of open filling system and rice of Chinese character shape structural design of horizontal runner, the ZL114A base casting applied to a tactical missile component had achieved a smooth filling from bottom to top and a progressive solidification from top to bottom under the low-pressure and additional chill conditions. The maximum size of the positive deviation was 0.7 mm, whereas the biggest negative deviation size was -0.8 mm when the shake-out time was selected to 14 h. The tensile strength, yield strength, elongation and Brinell hardness were 340.7 MPa, 265.7 MPa, 7.8% and HBS 94, respectively, after the T6 heat treatment within secondary solution and the low temperature stabilization, the grain size and distribution of strengthening phase Mg2Si and Si phase that distributed nearby the grain boundaries became more tiny and uniform, the fracture mechanism were dimple fracture and intergranular fracture.