Regulations on the allowable existence and repair scope of surface defects of copper alloy castings
A1 For surface defects of castings that are not specified in detail in drawings, technical documents or agreements, whether they can be repaired or shipped directly from the factory can be determined according to the scope listed in these regulations.
A2 Penetrating defects such as cracks and cold shut are not allowed on the surface of castings.
A3 As long as the appearance quality and usage requirements are not affected, defects within the following range are allowed to exist and can be shipped directly from the factory.
A3.1 Any defects that can be removed after processing are allowed on the surface of the casting to be machined.
A3.2 Oxidized inclusion defects on the non-machined surface of the casting are allowed to exist if the depth does not exceed the lower limit of the specified wall thickness and the area does not exceed 10% of the surface.
A3.3 For hole defects, according to the different working conditions of various surfaces of castings, the surface of castings is divided into four levels abcd. The levels shall be indicated by the purchaser in the drawings or technical documents. If the required party does not indicate the level, the supplier can determine the level according to Table A, and determine the allowable range of defects on the surface of each level according to Table A2 and Table A3 to determine whether it is allowed to be shipped directly from the factory. Non-machined surfaces can be treated as Class D. A3.3.1 The depth of a single hole defect shall be subject to the following regulations:
A3.3.1.1 The depth of a single hole allowed on the non-machined surface shall not exceed 25 mm.
A3.3.1.2 The depth of a single hole allowed to exist on the processed surface shall not be greater than 1.5 mm, and shall not exceed 1/3 of the wall thickness at that location: it shall not exceed 1/4 of the wall thickness on the installation edge.
A3.3.2 The depth of group hole defects shall be subject to the following regulations.
A3.3.2.1 Grouped holes are not permitted on Class A surfaces.
A3.3.2.2 The depth of the grouped holes on the Class B surface shall not be greater than 0 mm, and shall not exceed 1/4 of the thickness at that location.
A3.3.2.3 The depth of grouped holes on Class C surface shall not be greater than 1.5 mm, and shall not exceed 1/4 of the thickness at that location.
A3.3.2.4 The depth of grouped holes on Class D surfaces shall not be greater than 20 mm and shall not exceed 1/3 of the thickness at that location.
A3.4 Castings that are allowed to have surface defects of single holes and groups of holes shall not have similar defects on the symmetrical parts of the reverse side of the same section.
A4 casting surface finishing
A4.1 Surface defects of castings can be eliminated by grinding, but the dimensional tolerance after grinding should comply with the drawing requirements.
A4.2 Except for special provisions, if the scope of defects exceeds those specified in Table A2, repair methods are allowed. The repair area, number of repairs, and repair depth shall comply with the provisions of Table A4.
A4.3 The repaired defects must be ground smooth without affecting the appearance and normal use. There must be no cracks on the surface of the repaired casting.
A4.4 Unless otherwise specified in the drawings and technical agreement, the repair process can be decided by the manufacturer. The manufacturer should ensure the quality of the repair.
A4.5 Copper liquid or copper welding rods of the same or similar material should be used for repair. If the purchaser agrees, welding is allowed to be used for repair.
A4.6 Casting defects under the following conditions are not allowed to be repaired:
a. Pressure-bearing or sealed parts in contact with flammable, explosive or highly toxic substances;
b. Threaded parts that bear important stress;
c. Parts that are not allowed to be repaired according to the drawing or agreement;
d. Other repairs that seriously affect the appearance quality or performance.
Note: The diameter and depth of holes on the non-machined surface shall not be greater than 1.0mm, and the holes on the surface shall have a diameter less than 0.5mm and a depth less than 1.mm.
Not counted as a defect.
Note: The diameter and depth of holes on the non-machined surface are not greater than 1.0mm, and the holes on the machined surface are less than 0.5mm in diameter and less than 1mm in depth.
Not counted as a defect.
Note: 1. The welding repair area refers to the area after expansion. 2. Areas with a welding repair area less than 2cm² are not included in the number of welding repairs.
