Firstly, cast the steel castings of the coupler according to the original casting process design. The main problems exposed are: there are air hole defects on the large plane and side of the steel casting coupler body, and those with larger size must be welded, as shown in figure (a); There are sand inclusion, sand sticking and rough surface defects on many internal surfaces of the lower hook head, which must be cleaned and repaired by welding, as shown in figure (b); There is sand inclusion on the surface of coupler tail pin hole and the surface is rough, as shown in figure (c); Through magnetic particle flaw detection, micro cracks are found at the root of pouring riser, the corner of hook body and hook head and the corner of complex surface inside the hook head. Figure (d) (E) shows the situation after crack repair.
(e) Welding repair of inner corner cracks on hook head
After adopting the improved casting process scheme, the surface quality of the large plane on the hook body, the complex curved surface inside the steel casting hook head and the casting around the coupler tail pin hole is better. Although there are still defects such as pores, slag inclusion, sand sticking and rough surface from time to time, the size and occurrence probability are greatly reduced, and the number of cracks at the root of the pouring riser, the hook shoulder and the corner of the complex surface inside the hook head is greatly reduced. The above casting defects will be reasonably cut and Under the processing conditions such as welding repair, qualified steel castings of coupler body can be obtained. Will analyze the causes of casting defects in detail, put forward improvement measures, reduce processing workload and improve production efficiency.