Metal materials for precision casting and processing enterprises are mainly from outsourcing materials, scrap casting enterprises, and pouring risers. The outsourcing of metallic materials is usually large, rarely pressed into a cylindrical shape, and different material materials are easily confused, such as 316 materials mixed with 304 or 430 materials. Therefore, precision casting and processing companies choose to purchase cylindrical materials as much as possible. The chemical composition spectrum analyzer for each batch of purchased materials was analyzed. If possible, suppliers should conduct site visits and precision casting of materials to assess whether materials are identified, protected and isolated.

For corporate waste (waste castings, pouring pipes) in addition to corrosion, oil, sand and clean drying treatment, control S, P components. In addition, the scrap of different materials should be identified, reversed, stored separately, and cannot be confused.

Because the purpose of precision casting processing is different, the heat treatment is very large, and can be basically divided into two categories. First, the structure of the structure is not changed by heat treatment, and the second is the basic change of the structure. The first heat treatment procedure is primarily used to eliminate internal stresses that are caused by cooling conditions and conditions in the stainless steel casting process. Mechanical properties such as microstructure, strength, etc., are not affected by heat treatment and significant changes.

Precision casting materials

Major changes have been made to the second type of heat treatment and major Al Qaeda, which can be broadly divided into five categories:

1, softening annealing: its main purpose is to decompose the carbide, its hardness is reduced, improve the processing performance, for the ductile iron, the purpose is to obtain more ferrite.

2, normalizing treatment: the main purpose is to obtain pearlite and sorbite, improve the mechanical properties of stainless steel castings.

3, quenching: mainly in order to obtain higher hardness or wear strength, while having very high surface wear characteristics.

4, surface hardening treatment: mainly to obtain a surface hardened layer, while having very high surface wear characteristics.

5, precipitation hardening treatment: mainly to obtain high strength and elongation will not change drastically