Nine factors of casting porosity formation and 5 improvement measures of process (2)

1) The technological measures to prevent subcutaneous stomata mainly include: 2) Desulfurization treatment. The so-called desulphurization, that is, as far as possible, the sulfur in the molten iron is transferred to the slag, and then eliminated, the less FeS in the molten iron, the higher the desulphurization efficiency, appropriately increasing the basicity of the desulphurized […]

Nine factors of casting porosity formation and 5 improvement measures of process (1)

The subcutaneous blowhole is a common casting defect in wet-type Ductile Iron Castings, so it has a prevalent deficiency and is especially sensitive to thin-walled castings. The reason is that the thin-walled castings have a fast solidification speed. The gas can not form bubbles in time, and the thick-walled castings have a slow solidification speed […]

Detailed introduction of permanent mold casting process -4

After the casting process drawing, the metal mold design can be carried out. The design content mainly includes determining the structure, size, core, exhaust system, and ejector mechanism of the metal mould. The designed metal mold should be simple in structure, convenient in processing, reasonable in material selection, safe and reliable

Detailed introduction of permanent mold casting process -3

According to some characteristics of metal mold casting, the following points should be paid to when designing a gating system: The casting speed of metal is high, which is more than about 20% of the sand mold. Secondly, when the liquid metal is filled, the gas in the mold cavity should be removed smoothly, the […]

Detailed introduction of permanent mold casting process -2

There are three types of parting surface: vertical, horizontal, and comprehensive (vertical, horizontal mixed parting, or curved surface parting). The principles for selecting the parting surface are as follows:

Detailed introduction of permanent mold casting process -1

According to the characteristics of the permanent mold casting process, in order to ensure the casting quality, simplify the permanent mold structure and make full use of its technical and economic benefits, the structure of permanent mold casting must be analyzed and a reasonable casting process must be worked out.

Quenching and tempering technology of ductile iron castings

Austenitizing is the first step in the quenching of Ductile Iron Castings. The austenitizing temperature is 860-880 °C, and the holding time is 1 hour for every 25mm thick casting, which is the same as that of normalizing and annealing. After the insulation is finished, it cools quickly in the flowing air. After quenching, the castings […]