提升箱体铸造工艺设计及铸造过程数值模拟

Lifting box casting process design and numerical simulation

提升箱体材质为ZG25CrNiMo,主要形状特征为回转体,壁厚不均匀。选择“提环轴孔所在大面朝下,吊耳及厚大侧壁小端面朝上”的工艺方案,上、中、下三开箱造型,分别设置冒口、模型主体、芯头及浇道。冒口采用模数法设计,配合HZCAE11.0软件分别进行纯温场和充型传热耦合条件下的凝固模拟,确定出1个腰形明冒口和2个圆柱形明冒口在厚壁端面进行补缩。经多次模拟结果显示,厚大热节部位的缩孔基本消除,铸件中部两壁交接处、底部提环轴孔与内侧壁的交接处仍存在疏松,但已不能通过冒口补缩进行消除。为消除上述缺陷,在底部设置了外冷铁,以实现更好的顺序凝固和补缩。

The material of the lifting box is ZG25CrNiMo,and the main shape is characterized by a rotary body,and the wall thickness is uneven.Select the process scheme of"the large side of the lifting ring shaft hole is facing down,the lifting lug and the small end face of the thick side wall are facing up",and the upper,middle and lower three unboxing shapes are set up respectively,and the riser,model body,core head and sprue are set respectively.The riser was designed by the analog-digital method,and the solidification simulation under the coupling conditions of pure temperature field and filling heat transfer was carried out with the HZCAE11.0 software,and one waist-shaped open riser and two cylindrical open risers were determined to be compensated on the thick-walled end face.The simulation results show that the shrinkage porosity of the thick and large hot joints is basically eliminated,and there is still looseness at the junction of the two walls in the middle of the casting,the junction between the bottom ring shaft hole and the inner side wall,but it can no longer be eliminated by riser shrinkage.In order to eliminate the above defects,an externally cooled iron is provided at the bottom to achieve better sequential solidification and replenishment.