The formation of shrinkage porosity is due to the wide crystallization temperature range of the alloy, which tends to paste solidification mode. It is not solidified at the end. Due to poor feeding and unsmooth channel, shrinkage porosity defects may be formed. There has never been a very effective criterion to judge the shrinkage porosity defect of iron castings. On the basis of dynamic shrinkage, it is proposed to calculate the degree of shrinkage porosity defect to represent the possibility of shrinkage porosity of iron castings.
- Calculate the shrinkage or expansion of each isolated domain.
- Calculate the total volume of cells that can be filled in each isolated domain.
- If the tag is isolated from a unit without flow feeding, the tag may form a loose isolated domain.
- Judge the isolated domain marked in step 3. If the shrinkage of the isolated domain shows expansion, there will be no shrinkage defect; If the shrinkage amount of the isolated domain is shrinkage and can not get the lower shrinkage, it is likely to produce the isolated domain with shrinkage porosity. The degree of shrinkage porosity defect is marked according to the shrinkage amount. The greater the degree, the easier it is to produce shrinkage defects.