Affect the accuracy of bed castings, life expectancy

1, the hole in the bed castings inside, at or near the surface, there are different sizes of smooth eyelet, the shape of a round, long and irregular, there are single, there are gathered into pieces. Color white or with a dark layer, and sometimes covered with a layer of oxide. Reduce the amount of gassing metal smelting. Reduce the sand in the pouring process of gas evolution, improve bed castings structure, improve sand and core permeability, so that type of gas can be successfully discharged.

2, shrinking in the bed castings within the tiny and inconsistent shrinkage, gathered in one or more, coarse grains, there is a small hole between the crystal grain, seepage water pressure test. Wall joints minimize heat Festival, as far as possible to reduce the pouring temperature and pouring speed.

3, trachoma casting in the bed or inside the surface of a hole filled with sand. Strict control of sand performance and modeling operations, before cleaning the cavity should be noted.

4, cold cracking in the bed castings have penetrated or not penetrate the cracks (mainly straight), cracking metal skin oxidation.

5, cold in the bed castings have a not fully integrated gap or depression, the junction of the border is smooth. Increase pouring temperature and pouring speed. Improve the casting system. Continuous flow pouring.

6, sticky sand In the bed castings surface, all or part of the metal (or metal oxide) and sand (or paint) mixed (compound) or a layer of sand burning structure, resulting in bed castings rough surface.

Bed casting a wide range of uses

Can be used for instrumentation, electronics, light industry, standard parts, bearings, auto parts industry and other parts processing. Wear resistance and dimensional stability, a direct impact on the accuracy of bed castings to maintain life.