When there are pores in flange castings, the following process improvement measures are taken:
1. Change the sand mold brushing method
The brushing method of sand mold coating is changed from overall spraying water-based coating to overall spraying water-based coating plus local manual brushing alcohol based coating. When painting by hand, paint alcohol based paint. After painting, fire should be used in time to ensure the drying of these two deep holes.
2. Reduce the air generation of sand core in cold box
By adjusting the proportion of resin components in the sand core of the cold core box, on the premise of ensuring that the tensile strength of the sand core is ≥ 1MPa, adjust the proportion of components to reduce the gas generation.
3. Reduce the gas output of sand mold
Because the upper cylindrical core and inner cavity oil duct core are coated sand. On the premise of meeting the basic strength of sand core circulation and use requirements, it is better to develop low gassing coated sand with a gassing rate of about 12g / ml.