Common Precision Casting Defects

  Common precision casting defects

  Common precision casting defects have bubbles, bubbles are fine castings individual position showing lubrication hole eye defects. Bubbles are usually found after machining. Precision casting technology staff separation years of experience in the workshop, the precision casting of the reasons for the emergence of bubbles and preventive measures are summarized as follows:

  First, the composition of the reasons: 1. Most of the conditions of the bubble is mainly due to fine cast shell shell is not abundant, pouring molten steel when the shell suddenly produce a lot of gas can not be successfully discharged, and then into the metal liquid bubbles;

  2. Due to the shelling process or shell type of information, shell permeability is too bad, the cavity of the gas is difficult to discharge into the metal liquid to form bubbles;

  3. The air in the molten steel that is poured into the molten steel during casting is not discharged to form the casting bubbles.

  Second, the precautionary approach 1. In the case of precision casting conditions permit, in the construction of complex castings set up the highest bubble.

  2. In the design of the pouring system, to be fully aware of the shell exhaust demand.

  3. Shell firing temperature, time should be reasonable, the insulation time should be sufficient.

  4. Wax should be completely removed when the wax material.

  5. Properly reduce the pouring mouth to the gate cup spacing, pouring the speed to be uniform, to ensure that the degree of steel steady overflow cavity, as little as possible into the molten steel in the air, so that the cavity and the molten steel can be successfully discharged.