Reasons for easy cracking of the shell of pipe castings in precision casting

Reasons for easy cracking of the shell of pipe castings in precision casting

As stated on page 75 of Mr. Shanwu Yangshu's book "Practical Techniques for Precision Casting", spherical and cylindrical castings are most prone to shell cracking. Today, precision casting manufacturer Tianyao Metal will discuss the reasons behind this.

We know that when the shell is not fully dried, it is prone to cracking. The residual moisture in the binder in the shell can cause abnormal boiling during dewaxing, leading to local damage to the shell. The Practical Techniques for Precision Casting provide methods to improve shell cracks:

1. Soaking the silica sol shell in ethyl silicate hydrolysis solution or in phenol resin alcohol solution and polyvinyl alcohol solution before dewaxing can reduce shell cracking;

2. It is best to use wax with low melting point and low viscosity. This wax can easily melt out during the initial stage of rapid pressure, which can reduce the pressure on shell cracks.

In fact, the cracking of the shell is clearly a problem with the strength of the shell. This strength is reflected in two aspects: one is the dryness of the shell, and the other is the thickness of the shell. In addition, try to use as few solid objects as possible, which can affect the dewaxing speed and may cause cracking of the mold shell. If the temperature is too high, do not pull the mold shell out of the drying room if it is not dewaxed in time. If it needs to be pulled, handle it in a timely manner.

The above is the cause of cracking in pipe castings and corresponding treatment methods, hoping to be helpful to everyone.

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