GB/T 9438-2013Aluminum alloy castings (English PDF)

4.4 Geometrical Shapes, Dimensions and Weight Tolerances

4.4.1 The geometrical shapes and dimensions of the castings shall comply with the requirements of the drawings, and the dimensional tolerances of the castings shall comply with the provisions of GB/T 6414.

4.4.2 The weight of the castings shall comply with the requirements of the drawings or technical agreements, and the weight tolerances of the castings shall comply with the provisions of GB/T 11351.

4.5 Surface Quality

4.5.1 The surface roughness of the castings shall comply with the requirements of the drawings or technical agreements.

4.5.2 The castings shall be clean and free of burrs and trimmings. The pouring and casting heads on the non-machined surface shall be cleaned to be flush with the surface of the castings. The remaining amount of the pouring and casting heads on the surface to be machined shall be within the margin range specified in the drawings. If there is no special provision, it shall generally not be 5 mm higher than the surface of the castings, but it shall not affect the radiographic inspection.

4.5.3 No cold shuts, cracks, shrinkage cavities, penetrating defects and serious defects (such as: insufficient pouring and mechanical damage, etc.) are not allowed on the surface of the castings.

4.5.4 Any defects that can be removed by machining are allowed on the surface of the castings to be machined.

4.5.5 The area on the castings used as a machining reference shall be flat.

4.5.6 Unless otherwise specified, on the non-machined surface of metal castings, traces, such as: mold parting, misaligned boxes, ejector pins and exhaust plugs, are allowed, but the protrusions shall not exceed the surface by 1 mm, or the recesses shall not be 0.5 mm lower than the surface.

4.5.7 The non-machined surface and machined surface of sand mold and metal mold castings are generally allowed to have:

a) Single holes On the non-machined surface, the maximum diameter of single holes shall be not greater than 3 mm, and the depth shall not exceed 1/3 of the wall thickness. On the installation

5.1 Chemical Composition

The inspection method for the chemical composition of the castings shall comply with the provisions of GB/T 20975 (all parts) or GB/T 7999. Under the condition that the accuracy of analysis is guaranteed, other test methods are also allowed to be used. When there is a dispute over the analysis results, arbitration shall be conducted in accordance with GB/T 20975 (all parts).

5.2 Mechanical Properties

5.2.1 The tensile test shall be carried out in accordance with the provisions of GB/T 228.1.

5.2.2 The hardness test shall be carried out in accordance with the provisions of GB/T 231.1.

5.3 Surface Quality

5.3.1 Inspect the appearance quality visually or with appropriate measurement tools, instruments or test methods.

5.3.2 The roughness rating of the non-machined surface of the castings shall be carried out in accordance with the provisions of GB/T 15056.

5.3.3 The pinhole rating of the machined surface of the castings shall be carried out in The surface quality of the castings shall be inspected piece by piece.

6.3.5 Internal quality

6.3.5.1 Category-I and Category-II castings shall be subject to X-ray photography inspection in accordance with the provisions of the drawings and relevant technical documents. The inspection parts and proportions shall be agreed upon by the supply-side and the demand-side.

The inspection quantity shall be calculated in accordance with the number of castings poured in each smelting heat.

6.3.5.2 For blind spots that are difficult to perform X-ray photography inspection, sampling and anatomy inspection shall be agreed upon by the supply-side and the demand-side.

6.4 Determination and Re-inspection

6.4.1 Chemical composition

When the chemical composition of the alloy is disqualified in the first submission for inspection and analysis, re-sampling and analysis of the disqualified elements are allowed. If it still fails in the second analysis, then, the alloy in that smelting heat shall be determined as disqualified in chemical composition.

6.4.2 Mechanical properties

6.4.2.1 The inspection of mechanical properties of single cast specimens shall be carried out in accordance with the provisions of GB/T 1173. If the single cast specimens are disqualified in mechanical properties, and the attached cast specimens or bulk specimens are qualified in mechanical properties, then, the castings shall be determined as qualified in mechanical properties.

6.4.2.2 If castings in the same heat treatment state in one smelting heat are heat treated in different heat treatment heats, and the specimens in this smelting heat have been inspected and passed in one heat treatment heat, then, the castings from this smelting heat in another heat treatment heat may be delivered as qualified specimens from any smelting heat in the same heat treatment heat.

6.4.2.3 When the sampled bulk specimens of the castings are disqualified in mechanical properties, the sampling size may be doubled to perform a sampling inspection and perform re-sampling to inspect the mechanical properties. If the results of the doubled sampling size in sampling inspection are all qualified, then, the furnace (batch) of castings shall be determined as qualified in mechanical properties, otherwise, they shall be determined as disqualified. When the doubled sampling size for sampling inspection is still disqualified, sampling inspection after re-heat treatment is allowed, but heat treatment is only allowed to be repeated twice.

6.4.2.4 When the specimens have casting defects or the inspection result is disqualified due to fault of the test itself, it will not be counted in the number of inspections, but the specimens need to be replaced and re-submitted for inspection.

6.4.2.5 For castings are delivered in the as-cast state, when they are disqualified in mechanical properties, appropriate heat treatment is allowed on the castings, and the mechanical properties shall still be subject to acceptance inspection in accordance with the as-cast indicators.

6.4.2.6 When there are hardness requirements, follow the provisions of GB/T 1173. If they are disqualified in hardness, after repeating the heat treatment, carry out a re-inspection. If they are still disqualified after the third heat treatment, then, the castings shall be determined as disqualified.

6.4.2.7 When heat treatment is repeated due to disqualified hardness, in addition to the hardness inspection, the mechanical properties of single cast, attached cast or bulk specimens shall also be inspected in accordance with the original requirements.

6.4.3 Geometrical shapes, dimensions and weight tolerances of castings

If the geometrical shapes, dimensions and weights of the castings do not comply with the requirements of 4.4 in the inspection, then, the castings shall be determined as disqualified.

6.4.4 Surface quality

If the surface quality of the castings does not comply with the requirements of 4.5 in the inspection, then, the castings shall be determined as disqualified.

6.4.5 Internal quality

6.4.5.1 If the internal quality of the castings does not comply with the requirements of 4.6 in the inspection, then, the castings shall be determined as disqualified.

6.4.5.2 If the sampling inspection with X-ray photography is disqualified, a double size of specimens or castings shall be taken. If they are still disqualified, all castings shall be inspected one by one.

7.1 Marking

7.1.1 The castings shall be marked with the alloy code and melting furnace No. etc. in the designated parts of the drawings. The markings shall be clearly visible and traceable.

7.1.2 The castings shall be accompanied by a quality certificate, indicating:

a) Supply-side's name;

b) No. and title of the Standard;

c) Casting name and alloy designation (code);

d) Analysis results of chemical composition, inspection results of mechanical properties […]