| Name | Texture of material | Weight/kg | Length/mm | Width/mm | Height/mm | Maximum wall thickness/mm | Minimum wall thickness/mm |
| Gland | ZG230- 450 | 15.5 | 270 | 270 | 105 | 40 | 6 |
The gland plays a sealing and fixing role in the pump, which is crucial for the normal use and operation of the pump. As shown in the figure, the pump gland product weighs about 15.5kg and is made of ZG230-450. See Table 1 for specific structural parameters of steel castings, Table 2 for chemical composition, and Table 3 for mechanical properties. The maximum wall thickness of steel castings is 28 mm, and the minimum wall thickness is only 6 mm. It is required that the steel castings be free of defects such as shrinkage cavities, porosity, and cracks.
| Component | C | Si | Mn | P | S | Cu | Cr | Mo | Ni | V |
| Requirement | ≤0.30 | ≤0.50 | ≤0.90 | ≤0.04 | ≤0.04 | ≤0.30 | ≤0.35 | ≤0.20 | ≤0.30 | ≤0.05 |
| Control standards | 0.18~0.24 | 0.30~0.45 | 0.60~0.90 | ≤0.03 | ≤0.03 | ≤0.15 | ≤0.20 | ≤0.15 | ≤0.25 | ≤0.05 |
This steel casting has a small weight and a relatively simple overall structure, but it has many heat dissipation ribs, with a thickness of only 6mm, the shortest being 35mm, the longest being 170mm, and a height of 25mm. Through the analysis of the structure of the steel casting, there are two casting difficulties as follows:
(1) Steel castings with small rib plate thickness are prone to poor mold filling. In sand casting, when the size of carbon steel parts is between 200mm and 400mm, the minimum wall thickness of the casting should not be less than 9mm. The wall thickness of this casting is only 6mm, which has far exceeded the limit of sand casting production. Therefore, the molding of rib plates will be a key and difficult point for this steel casting.
(2) The pouring ladle used by an enterprise to produce steel castings is a 1.5t ladle, but the weight of this product is only 12.5kg. Due to the small quality of steel castings, when using a larger ladle for pouring, the pouring temperature, pouring time, and pouring process of the steel castings cannot be well guaranteed, which is very detrimental to the molding of the thin-walled parts of the steel castings.