As shown in the figure, the shrinkage casting defects produced by automobile steering knuckle during actual production are mostly distributed on the main hot joint. Shrinkage porosity not only affects the mechanical properties of ductile iron castings, but also affects product costs, including process yield and production efficiency. The...
Ductile iron is an important material in strong and tough cast iron. Its strength, plasticity and toughness are higher than other cast iron, and it has good vibration absorption and wear resistance. Based on the above characteristics of materials, ductile iron is widely used in construction machinery, energy machinery,...
1. Chemical composition detection The ARL3460 direct-reading spectrometer is used for chemical composition detection. The results of chemical composition detection are shown in Table 1. Value Wire feeding length/m Wire feeding speed/m · min^-1 Temperature before wire feeding/℃ Reaction time/s Pouring temperature/℃ Project 14.5±0.15 18±0.2 1 430～1 450 40～60...
1. Improvement of cavity arrangement process As shown in the figure, the improved ductile iron casting process changes the original strip arrangement into a star arrangement. The star arrangement is relatively concentrated, and heat sources are added to each other at the outer wall. The heat dissipation rate of...
The casting simulation software was used to simulate the mold filling and solidification process of the balance shaft support. Figure 1 shows the solidification process. The casting solidification can achieve sequential solidification. The simulation found that shrinkage porosity may occur at the position indicated in Figure 2. After solidification,...
(1) Ductile iron castings have large overall dimensions, high requirements for size and wall thickness control, large wall thickness difference, complex structure and easy to produce shrinkage defects. On the one hand, a reasonable parting and core separation scheme is needed to achieve accurate control of the size and...
In order to analyze the effect of Cu and Mn content on the mechanical properties of ductile iron casting, tensile tests were carried out on three groups of ductile iron casting samples. The figure is the engineering stress-strain curve of No. 1 ~ 3 ductile iron casting samples, and...
The lamellar spacing of pearlite will also affect the tensile strength of ductile iron casting. Generally, the smaller the lamellar spacing is, the higher the tensile strength is. In order to further observe the morphology of pearlite lamellae and explore the effect of alloy elements Mn and Cu on...
(1) Sample preparation. Using sheet tensile samples, first cut a sheet with a thickness of 2 mm from the middle of the cylindrical ductile iron casting test bar by wire cutting machine (considering the solidification sequence and solidification characteristics of ductile iron casting, the middle structure can better represent...
The most effective way to solve the internal shrinkage casting defects of nodular iron castings is to use chill and riser. The combination of the two cannot solve the problem. We must solve the problem from other angles. There is a large hot spot, so it is impossible to...