GB/T 3191-2019Extrusion rods and bars of aluminium and aluminium alloys (English PDF)

3.1 Product classification

3.1.1 Designation, supply status and dimensions

The designation, supply status and dimensions of the rods and bars shall comply with the requirements of Table 1. Rods and bars of other designations, supply statuses and dimensions, if required, shall be negotiated between the supplier and the buyer, and specified in the order form (or contract).

3.1.2 Marking and examples

Product markings are expressed in the order of product name, number of this Standard, designation, status and dimensions. Examples of markings are as follows. […]

3.8 Macro-structure

3.8.1 Cracks, shrinkage, and porosity are not permitted on the macro-structure samples of the rods and bars.

3.8.2 The layer depth on the macro-structure sample of the rods and bars shall not exceed half the negative deviation of the diameter of the rods and bars.

When unlayered rods and bars are required, it shall be negotiated between the supplier and the buyer and indicated in the order form (or contract).

3.8.3 Point defects such as bright grains, non-metallic inclusions, foreign metallic inclusions, white spots and primary crystals on the macro-structure sample of the rods and bars shall comply with provisions in Table 11.

3.10 Appearance quality

3.10.1 Cracks, bubbles or corrosive spots are not permitted on the surface of the rod.

3.10.2 Peeling on the surface of the rods and bars, if any, shall be removed; however, the diameter of the round rods and the thickness of the square rods or hexagonal rods after removal must not exceed the allowable deviation range.

4.1 Chemical composition

4.1.1 Perform routine chemical analysis only on the numerically specified elements other than those in the columns of the "Al" and "Other" of corresponding designations in GB/T 3190. When the mass fraction of the non-routine analysis element is suspected to exceed the limit value of this Standard, the producer shall analyze these elements.

4.1.2 The analysis method of chemical composition shall comply with requirements of GB/T 20975 or GB/T 7999; the arbitration analysis shall adopt the methods which are specified in GB/T 20975.

4.2 Dimensional deviation

4.2.1 Section dimensions

For the diameter of the round rods, and the thickness of the square rods or the hexagonal rods, use a caliper whose accuracy is not less than 0.02 mm or a measuring instrument of corresponding accuracy to perform the measurement.

4.2.2 Chamfer radius of square rods or hexagonal rods

For the chamfer radius of square rods or hexagonal rods, use measuring tools such as calipers, micrometers, R gauges whose corresponding accuracy is not less than 0.1 mm or special instruments to measure.

4.2.3 Vertical bending

Place the rod on the platform; when it becomes stable by its dead weight, place a 1 000 mm-long ruler (or knife ruler) against the surface of the rod along the length of the rod; use a feeler gauge to measure the maximum gap value hs between the surface of the rod and the ruler (or knife ruler); then, hs is the bending of the length of every 1 000 mm.

4.2.5 Twisting degree

For the twisting degree of square or hexagonal rods, place the rod on the platform and make one end of it close to the platform. When the rod is stable by its own weight, measure the gap values T1 and T2 between the two ends of the rod's raised ends and the platform, as the twisting degree of the rod, as shown in Figure 3. Use calipers, feelers or special tools to measure.

4.3 Room-temperature tensile mechanical properties

Perform the room-temperature tensile test according to the method that is specified in GB/T 16865.

4.4 High-temperature endurance tensile mechanical properties

Perform the high-temperature endurance tensile mechanical properties according to the provisions in GB/T 2039.

4.5 Ultrasonic flaw detection performance

Perform the ultrasonic flaw detection in accordance with GB/T 6519.

4.8 Appearance quality

Visually inspect the appearance quality under natural scattered light. If necessary, use dimensional measurement tools to define the defect size; determine the defect depth by grinding.

5.1 Inspection and acceptance

5.1.1 The product shall be inspected by the supplier to ensure that the product quality complies with the requirements of this Standard and the order form (or the contract); the supplier shall fill in the quality certificate.

5.1.2 The buyer shall inspect the received products in accordance with the provisions of this Standard. If the test result is inconsistent with the provisions of this Standard and the order form (or the contract), a written form shall be submitted to the supplier;

5.2 Batch

Products shall be submitted for acceptance in batches. Each batch shall consist of products of the same designation, status and dimensions; the weight of each batch is not limited.

5.3 Weight

The products shall be weighed on the scales (unless it is otherwise agreed by the supplier and the buyer).

5.4 Inspection items

5.4.1 Each batch of products, before being delivered, shall be inspected for chemical composition, dimensional deviation, room-temperature tensile mechanical properties and appearance quality.

5.4.2 For rods and bars whose diameter or thickness is not less than 20.00 mm, the macro-structure of each batch shall be inspected; for rods and bars whose macro-structure is less than 20.00 mm, the macro-structure shall be guaranteed by the supplier process.

5.4.3 Each batch of off-quenched rods and bars shall be inspected for microstructure.

5.4.4 When the buyer indicates in the order form (or contract) that the inspection of ultrasonic flaw detection performance is required, the inspection of ultrasonic flaw detection shall be performed.

5.6 Determination of the inspection result

5.6.1 When the chemical composition of any sample is unqualified, if the melting order of the rods and bars can be distinguished, judge the melting order of rods and bars that is represented by the sample as unqualified; inspect other melting orders of rods and bars in turn, and deliver the qualified ones. If the melting order cannot be distinguished, judge the batch as unqualified.

5.6.2 When the dimensional deviation of any of the samples is unqualified, judge the batch of rods and bars as unqualified.

6.1 Marking

6.1.1 Product marking

6.1.2 Package marking

The package marking of the product shall comply with the provisions of GB/T 3199.

6.2 Packaging

The rods and bars are not oiled or packed with paper. When the buyer requires oiling or padding, it shall be specified in the order form (or contract). Other packaging requirements are in accordance with GB/T 3199.

6.3 Transportation and storage

The transportation and storage of the rods and bars shall comply with the provisions of GB/T 3199.

6.4 Quality certificate

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

a) the name of the supplier;

b) product name.

c) designation, status, dimensions;

d) product batch number or date of manufacture;

e) net weight or number of pieces;

f) various of analysis and test results;

g) the inspection stamp of the supplier's quality inspection department;

h) code of this Standard;

i) date of packaging (or date of manufacture).