Features: A relatively regular hole is formed on the surface or inside of the steel casting, the shape of which is consistent with the shape of the sand. When the steel casting has just come out of the mold, the sand embedded in the surface of the casting can be seen, and the sand can be pulled out. When multiple tracheae exist at the same time, the surface of the casting is orange peel.
Reason: Holes are formed because the sand particles falling on the surface of the core are surrounded by the molten metal and the surface of the casting.
1. The surface strength of the sand core is not good, it has been charred or not fully cured.
2. The size of the sand core does not match the external mold. When closing the mold, the sand core is crushed.
3. Immerse the mold in sand-contaminated graphite water.
4. The sand is wiped off by the sand core at the ladle and the runner is washed with copper water.
prevention:
1. Sand cores are produced strictly with the process, remember to check the quality.
2. The sand core's size matches the external mold's size.
3. Clean the ink in time.
4. Avoid friction between ladle and sand core.
5. Blow out the sand in the cavity when putting down the sand core.