GB/T 33950-2017The continous roll-casting strips of aluminium and aluminium alloy (English PDF)

3.1 Longitudinal thickness difference

The maximum difference between the thickness of any two points at the same distance from the edge measured along the longitudinal direction of the continuous roll-casting strips.

3.2 Edge thickness

The thickness measured at 50 mm from the side edge of the continuous roll-casting strips (see H1, H2 in Figure 1).

3.3 Edge thickness difference

The difference between the thickness of the two edges measured at 50 mm from both side edges (see H1, H2 in Figure 1) on any cross-section of the continuous roll-casting strips.

3.4 Adjacent points thickness difference

The thickness difference between any two thickness measurement points of 100 mm apart [such as H0 and Hm1 (or Hn1), Hm1 and Hm2, Hn1 and Hn2 in Figure 1] on any cross-section of the continuous roll-casting strips.

5.3 Dimensional deviation

5.3.1 USE a micrometer with a precision of not less than 0.01 mm (or the same-precision measuring tool), at any point of the test piece of the continuous roll-casting strips not less than 50 mm from the edge, to measure the edge thickness of the continuous roll-casting strips. According to the measurement positions shown in Figure 1, MEASURE the thickness of each point.

5.3.2 On the test piece of the continuous roll-casting strips, USE a steel plate (tape) ruler with a precision of 1 mm or a measuring tool of corresponding precision to measure the width of the continuous roll-casting strips.

5.3.3 Calculate the edge thickness difference (3.3), adjacent points thickness difference (3.4), intermediate crown (3.5), and the relative transverse thickness difference (3.7) of each test piece. Calculate the maximum difference in the measurement results of the thickness at points equidistant from the edge between the test pieces, i.e. longitudinal thickness difference (3.1). Calculate the maximum difference in the measurement results of the intermediate crown between the test pieces, i.e. intermediate crown difference (3.6).

5.3.4 The dislocation layer and tower-shape of the continuous roll-casting strips are measured using a steel plate (tape) ruler with a precision of 1 mm or a measuring tool of corresponding precision.

5.4 Tensile mechanical properties at room temperature

The room-temperature tensile test of the continuous roll-casting strips is carried out in accordance with the provisions of GB/T 16865.

5.5 Macrostructure

The microstructure test of the continuous roll-casting strips is carried out in accordance with the provisions of GB/T 3246.2.

5.6 Inspection method of appearance quality

The appearance quality is visually inspected and, if necessary, measured using a steel plate (tape) ruler with a precision of 1 mm or a measuring tool of corresponding precision.

6.1 Inspection and acceptance

6.1.1 The continuous roll-casting strips shall be inspected by the supplier, to ensure that the quality of the strips meets the requirements of this Standard. The quality certificate shall be filled out.

6.1.2 The purchaser shall inspect the received continuous roll-casting strips in accordance with the provisions of this Standard. When the inspection result is inconsistent with the provisions of this Standard and the order form (or contract), it shall be submitted to the supplier in writing and shall be settled by negotiation between the supplier and the purchaser. Any objection to the appearance quality shall be filed within 1 month from the date of receipt of the continuous roll-casting strips. Any other objection shall be filed within 3 months from the date of receipt of the continuous roll-casting strips. If arbitration is required, the arbitration sampling shall be made at the purchaser place and jointly carried out by both the supplier and the purchaser.

6.2 Lot grouping

The continuous roll-casting strips shall, in coils, be submitted for acceptance.

6.3 Weighing

The continuous roll-casting strips shall be weighed in coils.

6.4 Inspection items

6.4.1 Each lot of continuous roll-casting strips, before leaving the factory, shall be inspected for chemical composition, edge thickness deviation, width deviation, edge thickness difference, intermediate crown, macrostructure, and appearance quality.

6.4.2 The continuous roll-casting strips shall be sampling-inspected for longitudinal thickness difference, adjacent points thickness difference, the relative transverse thickness difference, intermediate crown difference, and hydrogen content.

6.4.3 The mechanical properties and slag content are guaranteed by the supplier process. When the purchaser requires the mechanical properties and inspection, print the following mark (or attach a label):

a) Product name;

b) Designation;

c) Dimension specifications;

d) Product lot number or coil number;

e) Net weight;

f) Inspection imprint of the quality inspection department of the supplier or inspection imprint of the quality inspector.

7.1.2 Packing marking

The packing marking of the continuous roll-casting strips shall comply with the provisions of GB/T 3199, or otherwise agreed between the supplier and the purchaser.

7.2 Packing, transporting, storing

The method of packing the continuous roll-casting strips shall be stated in the order form (or contract). Other packing, transporting, and storing requirements shall be in accordance with GB/T 3199.

7.3 Quality certificate

Each lot of the continuous roll-casting strips shall be accompanied by a product quality certificate indicating:

a) Name, address, telephone number, and fax of the supplier;

b) Product name;

c) Designation, dimension specifications;

d) Lot number or coil number;

e) Net weight;

f) This Standard number;

g) Inspection results of various analysis items and imprint of the technical supervision department;

h) Packing date (or exit-factory date). […]