1: Reasons for dewaxing.
The pressure of dewaxing kettle is required to reach 66s. 5kg within 14 seconds. The dewaxing kettle of one unit in the same industry needs more than 1 minute to reach the pressure. So this is the reason for the shell crack of this unit, so we need to check whether there is a problem with the equipment. Whether the furnace wire is broken; Whether the pressure gauge is normal; Whether the sealing ring leaks. The dewaxing time is generally 6-10 minutes, which does not need to be too long.
2: Reasons for raw materials.
Whether the silica sol is invalid; Whether the mullite powder has quality problems, whether the slurry is caked or whether the content of impurities such as iron inside is high; Whether the slurry mixing time is in place; Whether the slurry is deformed.
3: Process planning reasons.
Whether the inner gate runner is small; The location planning is unreasonable, and whether the wax mold and die head have sharp corners.
4: Reasons for improper operation.
Whether the slurry is thick and uniform during shell making; Whether the floating sand on the surface of each layer of shell is cleaned and the next layer is made; Whether the ambient humidity of the surface layer and two layers is low and the drying is too fast, causing microcracks.
5: The temperature of baking or pouring molten steel is improper.
The sealing of the oven is poor, the temperature in the oven is uneven, and the point temperature exceeds 1200 degrees. The temperature of molten steel is too high.
Qingdao Xinnuoke Holdings Group limited company.