GB/T 40123-2021Aluminium and aluminium alloy billet with high purity and fine grain (English PDF)

4.1 Product designation, state and size specifications

The designation, state and size specifications of the billet shall comply with YS/T 67. When there are special requirements, the supplier and the purchaser shall negotiate and indicate in the purchase order (or contract).

4.2 Marking and example

The marking of the billet is indicated in the order of product name, number and sequence number of this Standard, designation, state (when it is cast state, it shall not be marked), and size specifications. A marking example is as follow:

The homogenized billet, of which the designation is 6061, the diameter is 254mm, the length is 6000mm, is marked as: Billet GB/T 40123-6061 homogenization-Phi254×6000

7.3 Purity

7.3.1 Hydrogen content

The measurement of liquid hydrogen shall comply with the method specified in YS/T 600.

7.3.2 Slag content

The off-line slag measurement shall comply with the method specified in GB/T 32186.

7.4 Macrostructure

The determination of macrostructure shall comply with the method specified in GB/T 3246.2.

7.5 Microstructure

7.5.1 Over-burning

The determination of over-burning shall comply with the method specified in GB/T 3246.1.

7.5.2 Non-metallic inclusions

The determination of non-metallic inclusions shall comply with the method specified in GB/T 3246.1. Conduct grinding and mechanical polishing of the specimen. After polishing, the specimen is rinsed with alcohol and then blown dry. Under a metallurgical microscope, use 200 times magnification to scan the inspection surface of the specimen. Use 500 times magnification to judge the observed non-metallic inclusions. Use 200 times magnification to measure the size of the confirmed non-metallic inclusions.

7.5.3 Segregation layer thickness

The thickness detection of the segregation layer shall comply with the method specified in Annex B.

7.5.4 Grain size

The determination of grain size shall comply with the method specified in GB/T 3246.1.

7.5.5 Dendrite spacing

7.5.5.1 Specimen preparation and erosion determination shall comply with the methods specified in GB/T 3246.1. Under the metallographic microscope, use 100 times magnification to observe the etched sample. The specimen shall show clear dendrites under a metallurgical microscope. Otherwise, the sample shall be re-prepared until it shows clear dendrites.

7.5.5.2 The measurement of the dendrite spacing of the etched specimen shall comply with the intercept method specified in GB/T 3246.1. For the measurement of dendrite spacing, no less than 50 dendrite spacings shall be selected.

7.5.5.3 Calculate the ratio of the maximum spacing of the measured dendrites to the average spacing.

7.5.6 Percentage of unmelted phase area

The percentage of unmelted phase area shall be determined according to the method specified in Annex C.

7.5.7 Phase conversion rate

The phase inversion rate shall be determined according to the method specified in Annex D.

7.6 Ultrasonic flaw detection

Ultrasonic flaw detection shall comply with the method specified in YS/T 874-2013.

7.7 Appearance quality

Under natural scattered light, visually inspect the appearance quality of the billet.

When necessary, size measuring tools can be used to determine the size of the defect. Determine the depth of defects by grinding.

8.1 Inspection and acceptance

8.1.1 The billet shall be inspected by the supplier to ensure that the quality of the billet meets the requirements of this Standard and the purchase order (or contract). Fill in the quality certificate.

8.1.2 The purchaser shall inspect the billet received in accordance with the provisions of this Standard. If the inspection result does not conform to the provisions of this Standard and the purchase order (or contract), it shall be submitted to the supplier in written form, and the supplier and the purchaser shall negotiate and resolve it. Objections that belong to the appearance quality and size deviation shall be raised within one month from the date of receipt of the billet. Objections pertaining to organization and performance shall be raised […]

8.6

8.6.7 When the ultrasonic flaw detection of any billet is unqualified, determine that the billet is unqualified. Inspect the other billets one by one. Only the qualified ones shall be delivered.

8.6.8 When the appearance quality of any billet is unqualified, the billet is judged to be unqualified. Inspect the other billets one by one. Only the qualified ones shall be delivered.

9.1 Marks

9.1.1 Product mark

The qualified billet shall include the following identification (or paste the label containing the following content):

a) Product name;

b) Lot number, melting number, casting number, root number;

c) Designation, state, size specification;

d) Inspection seal of the supplier's quality supervision department;

e) Bar code (when required);

f) Reference to this Standard.

9.1.2 Packaging marks

It shall be in accordance with GB/T 3199.

9.2 Packaging, transportation, storage

The billets are packaged as bare parts. Transportation and storage shall be carried out in accordance with the regulations of GB/T 3199.

Other packaging, transportation, and storage methods can be negotiated between the supplier and the purchaser and specified in the purchaser order (or contract).

9.3 Quality certificate

Each batch of billets shall be accompanied by a product quality certificate, which shall include the following:

a) Supplier's name, address;

b) Product name;

c) Designation, state, size specification;

d) Lot number, melting number, casting number;

e) Weight (gross weight, net weight);

f) Exit-factory inspection results of each analysis item and the inspection seal of the supplier's quality supervision department;

g) Packing date (or exit-factory date);

h) Reference to this Standard.