What are the common precision casting defects

Date:12-05-2018

The common precision Stainless Steel Casting Parts defects are air bubbles, and the air bubbles refer to the lubrication hole defects at individual positions of the fine casting. Bubbles are usually found after machining. Jibang precision casting technicians have separated many years of workshop consumption experience. The reasons for the presence of bubbles in precision casting and their prevention methods are summarized as follows:

First, the causes:

1. The appearance of bubbles in most cases is mainly due to the fact that the fine cast outer shell is not sufficiently roast. When the molten steel is poured, a large amount of gas cannot be discharged smoothly during the pouring of the shell, and bubbles are intruded into the molten metal to form bubbles.

2. Because of the shell technology or shell type data, the air permeability of the shell is too bad, the gas in the cavity is difficult to discharge, and bubbles are formed in the molten metal.

3. Casting bubbles formed when air trapped in molten steel fails to drain during casting

Second, preventive measures

1. Under the condition of precision casting conditions, set the row of bubbles at the highest point of the complex structure of the casting

2. When designing the gating system, it is necessary to fully consider the shell exhaust requirements

3 type shell baking temperature, time should be reasonable, holding time should be sufficient

4. The wax should be thoroughly cleaned when dewaxing

5. Properly reduce the gap between the ladle nozzle and the gate cup, and the pouring speed should be averaged to ensure that the steel level is stable enough to fill the cavity, and the air in the molten steel is as little as possible so that the gas in the cavity and molten steel can be discharged smoothly.