Long-term results of the measurements investment casting and casting size shows that in casting the longitudinal direction of the long 25mm size, the lost wax casting deviation more than 50% of the total deviation; when casting size increases, the impact is relatively reduced investment casting, for long 250mm, investment casting bias accounted for about 40% of the total deviation member. Lost Wax size deviation is mainly due to instability caused by molding process, such as the size of the force-fitting, pressure wax temperature, pressure injection pressure, dwell time, temperature-pressure, time-open, cooling, temperature fluctuations caused by other factors investment casting size deviation. Therefore, investment casting has great influence on the dimensional accuracy of precision stainless steel casting. In order to reduce the impact of lost wax casting stainless steel size deviation size, should pay attention to the following aspects: 1, using linear shrinkage small mold material, and to keep the mold material process performance (timely supplemented with new wax, dewaxing process). 2, to ensure that the working environment temperature, temperature, storage time and attention to the size of high precision investment casting modulus after. Uniform 3, when manual pressure wax, note the locking force, dwell time and reasonable modulo time. 4, equipment factors, the impact of thermal expansion shell casting size, and thermal expansion of the shell and the shell material and system and process related.
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