GB/T 6893-2022Aluminium and aluminium alloys cold drawn (rolled) tubes (English PDF)

3.1 Coiled tubes

Tubes, that are drawn through dies to final dimensions AND delivered in coils.

4.1 Category, designation, status, size specification

The category, designation, status, size specifications shall meet the requirements in

5.1 Aluminum alloy tubes for aviation

See Appendix A for the process control of aluminum alloy tubes for aviation.

5.3 Others

Where there are quality assurance requirements for other types of tubes, it shall be determined through negotiation between the supplier and the purchaser.

6.1 Chemical composition

The chemical composition of the tube shall comply with the provisions of GB/T 3190.

6.2 Dimensional deviation

The dimensional deviation of the tube shall comply with the provisions of the ordinary grade in GB/T 4436-2012.If other grades in GB/T 4436-2012 are required, it shall be determined by the supplier and the buyer through negotiation AND specified in the order (or contract).

6.4 Flaring performance

6.4.1 There shall be no cracks on the surface of 5B02 alloy tubes for aviation use, after the flaring test.

6.5 Compression test

There shall be no cracks on the surface of 1035 alloy's O status tubes for aviation use,

6.8 Air tightness

When the buyer has airtight requirements for the seamed tube, it shall be determined through negotiation between the supplier and the buyer, AND indicated in the order form (or contract).

6.9 Microstructure

The microstructure of the quenched tube shall not have over-burning.

6.10 Macrostructure

The surface grain size of 3A21 aluminum alloy tubes for aviation shall be better than the second grade in GB/T 3246.2.If the purchaser has macrostructure requirements for other alloys, it shall be determined through negotiation between the supplier and the purchaser AND specified in the order form (or contract).

6.11 Solderability

Seamed tubes shall not have poor welding.

6.15 Appearance quality

6.15.1 The surface of the tube shall be the original processed surface; the inner and Salt spray corrosion resistance level Test duration Designation Status Tube wall thickness Corrosion depth outer surfaces of the tube shall be smooth and clean.

7.1 Chemical composition

7.1.1 The chemical composition analysis method shall comply with the provisions of

GB/T 20975 (all parts) or GB/T 7999.The arbitration analysis method shall adopt the method specified in GB/T 20975 (all parts).

7.1.2 The calculation of "Al" content shall comply with the provisions of GB/T 3190.

When calculating the "Al" content, the sum -- of the analytical values of conventionally analyzed elements and unconventional analyzed elements suspected to be excessive -- is taken as the "sum of element content".

7.2 Dimensional deviation

The measurement method of dimensional deviation shall be carried out, according to the provisions of GB/T 4436-2012.

7.3 Mechanical properties

The tensile mechanical property test at room temperature shall be carried out, according to the provisions of GB/T 16865.

7.5 Compression test

The compression test shall be carried out, according to the provisions of GB/T 3251.

7.6 Flattening test

The flattening test shall be carried out, according to the provisions of GB/T 246.

7.7 Bending test

The bending test shall be carried out, in accordance with the provisions of GB/T 244.

The bending angle shall be determined through negotiation, between the supplier and the buyer, meanwhile it shall be specified in the order form (or contract).

7.14 Eddy current testing

The eddy current flaw detection shall be carried out, according to the provisions of GB/T 5126.

7.15 Appearance quality

Status Flaring rate % Designation Visual inspection is used for the appearance quality. When the depth of the defect cannot be determined, the grinding method can be used for measurement. For tubes which have an inner diameter of 12 mm ~ 50 mm, the inner surface can be inspected with an endoscope.

8.2 Group-batching

The tubes shall be submitted for acceptance in batches. Each batch shall be composed of the same category, designation, status, size specification. The batch weight is not limited.

8.3 Weighing

Tubes shall be weighed to check their weight (unless otherwise agreed upon by both parties).

8.5 Sampling

Sampling shall comply with the provisions of Table 10.

9.1 Marking

9.1.1 Product marking

Marks shall be made on the tubes that pass the inspection. The marks shall at least include the following contents.

9.1.2 Packaging box marking

The packing box mark of the tube shall comply with the provisions of GB/T 3199.

9.3 Quality certificate

Each batch of tubes shall be accompanied by a product quality certificate, which indicates.