Castings are parts manufactured using casting processes.
Due to the uncontrollable and complex nature of the manufacturing process, castings often contain defects to a certain extent. To ensure the quality of castings, it is necessary to assess the defects and classify them according to certain standards. Common casting defects include porosity, inclusions, looseness, cracks, and shrinkage cavities.
II. Requirements for Determining the Classification of Common Casting Defects
Porosity: Porosity is one of the most common defects in castings, mainly formed by the release of gas during the solidification process of the casting material. The classification of porosity is mainly based on the diameter and number of pores, generally divided into three levels:
(1) Level I: Single pore diameter ≤ 3 mm, ≤ 3 pores per square decimeter;
(2) Level II: Single pore diameter ≤ 5 mm, ≤ 10 pores per square decimeter;
(3) Level III: Single pore diameter > 5 mm, > 10 pores per square decimeter. Inclusions: Inclusions refer to the presence of impurities in castings, generally caused by inclusions in the melt or slag. The determination of inclusion levels is mainly based on the number and size of the inclusions, generally divided into three levels:
(1) Level I: Individual inclusion diameter ≤ 3 mm, ≤ 3 inclusions per square decimeter;
(2) Level II: Individual inclusion diameter ≤ 5 mm, ≤ 10 inclusions per square decimeter;
(3) Level III: Individual inclusion diameter > 5 mm, > 10 inclusions per square decimeter.
Porosity: Porosity is the phenomenon of internal voids in castings, generally caused by poor melt flow or uneven shrinkage during melt solidification. The determination of porosity is mainly based on the number and size of voids, generally divided into three levels:
(1) Level I: Single void diameter ≤ 3mm, ≤ 3 voids per square decimeter;
(2) Level II: Single void diameter ≤ 5mm, ≤ 10 voids per square decimeter;
(3) Level III: Single void diameter > 5mm, > 10 voids per square decimeter.
Cracks: Cracks refer to fissures or cracks in castings, generally caused by thermal or mechanical stress exceeding the material strength. The determination of crack levels is mainly based on crack length and number, generally divided into three levels:
(1) Level I: Single crack length ≤ 3mm, ≤ 3 cracks per square decimeter;
(2) Level II: Single crack length ≤ 5mm, ≤ 10 cracks per square decimeter;
(3) Level III: Single crack length > 5mm, > 10 cracks per square decimeter. Shrinkage Cavities: Shrinkage cavities refer to voids caused by material shrinkage in castings, similar to porosity. The determination of shrinkage cavity levels is mainly based on the cavity diameter and number, generally divided into three levels:
(1) Level I: Single shrinkage cavity diameter ≤ 3 mm, ≤ 3 shrinkage cavities per square decimeter;
(2) Level II: Single shrinkage cavity diameter ≤ 5 mm, ≤ 10 shrinkage cavities per square decimeter;
(3) Level III: Single shrinkage cavity diameter > 5 mm, > 10 shrinkage cavities per square decimeter.
The determination of defects in pump castings is an important indicator for evaluating casting quality, and different defects have different determination levels. The impact of casting defects on casting performance also varies, requiring evaluation and handling based on specific circumstances. Of course, professional foundry manufacturers will strictly avoid these defects. For example, Mulan Manufacturing Group. If you have a large demand for customized castings, you can entrust Mulan Manufacturing Group to produce them. Mulan Manufacturing Group has 13 years of experience in casting production and ships to Europe, America, Japan and South Korea all year round. It has complete certifications and looks forward to your cooperation and consultation.
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