The causes of shrinkage cavity and porosity of nodular cast iron are complex. The main factors affecting primary shrinkage, volume expansion and secondary shrinkage are metallurgical quality and cooling rate of molten iron, as well as the effect of spheroidizing and inoculation treatment. The metallurgical quality of nodular cast...
The solidification process of ductile iron is generally a process of shrinkage, expansion and re shrinkage. Although the precipitation of graphite can bring volume expansion in the solidification process of ductile iron, due to its paste solidification mode (the precipitation of a large number of dendrites separates the liquid...
In the high temperature compression test of Al Si based casting materials, the samples have compression deformation under different temperature and different strain rate environment, and its properties can be used to understand the characteristics of solidification shrinkage deformation of casting. During the solidification process of the shell casting...
Shrinkage is the physical nature of the alloy. Under normal pouring temperature, the shrinkage volume of the alloy with fixed composition cannot be changed, but this does not mean that the shrinkage cavity of the casting is inevitable. It has been proved that the compact castings without shrinkage cavity...
The effect of mold conditions on the shrinkage tendency of castings is mainly due to mold wall expansion. On the other hand, it depends on the pressure of molten iron itself. For the mold wall rigidity, it can be mainly summarized as two points: the tensile strength of molding...
The effect of phosphorus on the shrinkage defects of castings is shown in two aspects: one is that phosphorus, as a graphitization promoting element, can increase the graphite expansion in cast iron, and it can also improve the fluidity of molten iron, both of which can improve the feeding...
For many foundries whose production mode is from cupola to induction furnace, there is also a running in process for sulfur composition control. In fact, the effect of adding sulfur in coke in cupola is equivalent to a continuous process of increasing sulfur in molten iron, so it is...
The composition control of molten iron plays a very important role in the process design of casting anti shrinkage. Zhang Ruifen, a senior engineer of zhycasting, thinks that the main influencing factor of shrinkage defect is the chemical composition of cast iron, while Li Shuhui, a senior engineer of...
Although the anti shrinkage factor is a factor that must be considered in the casting process, recently, with the market demand for casting performance is higher and higher. Therefore, when designing the anti shrinkage process of castings, the use performance of castings, such as mechanical properties of castings, must...
This type of beam is one of the main parts of a large machine tool. The quality of the casting is 28.9t, the material is gray cast iron, which belongs to large cast iron. The internal part of the casting is a “ten” type tie bar structure, with a...