Stainless steel precision casting processing difficulties and details of process characteristics

Stainless steel precision casting processing details process features:
1. Since the shrinkage of stainless steel precision casting greatly exceeds the cast iron, in order to prevent shrinkage and shrinkage defects of the casting, most of the casting process uses risers, cold irons and subsidies to achieve sequential solidification.

2. Due to the poor fluidity of the molten steel, in order to prevent the cold separation and pouring of the steel castings, the wall thickness of the steel castings should not be less than 8 mm; the structure of the casting system is simple and the cross-sectional size is larger than that of cast iron; Or hot-casting type; suitable to increase the pouring temperature, generally 1520 °~ 1600 °C, because the pouring temperature is high, the molten steel has a high degree of superheat, a long time to keep the liquid, and the fluidity can be improved. However, if the pouring temperature is too high, it will cause defects such as coarse crystal grains, hot cracks, pores and sand.

Therefore, generally small, thin-walled and complex-shaped castings have a casting temperature of about +150 ° C of the melting point of steel; casting temperatures of large and thick-walled castings are about 100 ° C higher than their melting points.

Difficulties in stainless steel precision casting:
1. Stainless steel precision casting processing and hardening: the work hardening tendency during cutting is large, and the cutting of the tool in the work hardening area shortens the tool life.

2. Large cutting force and high cutting temperature: This type of material has high strength, large tangential stress during cutting and large plastic deformation, so the cutting force is large. In addition, the thermal conductivity of the material is extremely poor, and the high temperature tends to concentrate in the narrow area near the cutting edge of the tool, thus accelerating the wear of the tool.

3. Stainless steel precision casting processing easy to stick knife: no matter any stainless steel, there are characteristics of strong chipping and high cutting temperature during processing. When the strong chips flow through the rake face, the tool wear is accelerated.

4. The tool wear is accelerated, the material generally contains high melting point elements, plasticity, high cutting temperature, which makes the tool wear faster, sharpening the knife and changing the tool frequently, which affects the production efficiency and improves the tool use cost.