GB/T 221-1984 Quality standards for cold-rolled aluminium and aluminium alloy sheets and strips
1 Scope
This standard specifies the appearance and marking, technical requirements, testing methods and inspection rules of cold-rolled aluminum and aluminum alloy sheets and strips.
2 Normative references
This standard refers to the following documents in terms of technical terms and described techniques. For alI dated documents, only undated versions apply to this standard. For all undated documents, the latest version (including amendments) applies to this standard.
GB/T194 Standard binding strips
3 Appearance and marking
3.1 Appearance
The appearance of cold-rolled aluminum and aluminum alloy sheets and strips should meet the requirements of Table 1.
Table 1 Appearance of cold-rolled aluminum and aluminum alloy sheets and strips
Appearance Rolling direction Rolling pattern Round hole Side hole Straight lines Crossed lines
The length of the straight line should not be less than 5mm, and the length of the intersection line should not be less than 3mm.
The round hole cut in the middle should be evenly distributed, and there should be no large open holes. Its smallest interval should not be less than 10mm, and the size should meet the requirements of Table 2.
Table 2 Specifications of round holes
Width of strip Round hole diameter/mm Width of strip Round hole
diameter/mm Less than 0.15 0.25 0.3≤Width≤0.6 0.5 0.15≤Width<0.3 0.4 0.6＜Width≤2.0 0.8
(2) The side holes of the sheet should be equally distributed, and there should be no large open holes on the surface of the sheet. The largest distance between side holes should not be more than 100 mm, and the size should also meet the requirements of Table 2.
3.2 Marking
The trade name and variety of aluminum and aluminum alloy sheets and strips should be marked on the packaging products or product documents; in addition, when the thickness of the sheet demands measurement accuracy, the thickness tolerance should be marked on the product documents.
4 Technical requirements
4.1 Thickness
The thickness of aluminum and aluminum alloy sheets and strips should meet the requirements of Table 3.
Table 3 Thickness of aluminum and aluminum alloy sheets and strips
Sheet variety Aluminum and aluminum alloy sheets and strips Thickness/mm Sheet thickness tolerance/mm Aluminum aluminum alloy plates 0.15～2.0 ±0.02
4.2 Mechanical properties
The mechanical properties of aluminum and aluminum alloy sheets and strips should meet the requirements of Table 4.
Table 4 Mechanical properties of aluminum and aluminum alloy sheets and strips
Sheet variety Tensile strength/MPa Yield strength/MPa Elongation/% Aluminum aluminum alloy sheets and strips ≥160 ≥110 ≥8
5 Test method
5.1 Thickness test
The thickness of aluminum and aluminum alloy sheets and strips should be measured with a thickness gauge. When the thickness of the sheet requires measurement accuracy, the thickness tolerance should also be tested in accordance with the relevant provisions.
5.2 Mechanical properties test
The mechanical properties of aluminum and aluminum alloy sheets and strips should be tested in accordance with the following requirements:
(1) Obtain the sample by shearing according to GB/T 194;
(2) Tensile specimens should be tested according to GB/T 1040;
(3) The elongation rate should be tested in accordance with GB/T 1566.
6 Inspection rules
6.1 Sampling
(1) The product inspection is divided into a single inspection, a batch inspection and a monthly inspection.
(2) The inspection of finished products in single, batch and monthly inspection should be carried out in accordance with the provisions of Table 5.
Table 5 Sampling plan of finished products
Products name Sheet variety Total number of
samples Single inspection Batch inspection Monthly inspection Finished products Aluminum and aluminum alloy sheets and strips ≤200 pieces 2 pieces 5 pieces 2 pieces
(3) Random inspection on the finished products that have been delivered to the warehouse should be performed in accordance with Table 6.
Table 6 Sampling plan of finished products that have been delivered to the warehouse
Product name Sheet variety Total number of
samples Sampling plan Finished products delivered to the warehouse Aluminum and aluminum alloy sheets and strips ≤100 pieces 2 pieces
6.2 Test
(1) Test the appearance, and test the thickness, mechanical properties and other indicators if necessary.
(2) Sample the product according to the sampling plan of finished products
(3) Store the sample after the test is completed.
6.3 Inspection results
The inspection of the tested samples of aluminum and aluminum alloy sheets and strips should meet the requirements of this standard, otherwise the sample should be regarded as unqualified.
7 Marking, packaging and quality certificate
7.1 Marking
(1) Mark the name of the product, the variety and standard number, the manufacturer name or mark, and affix the corresponding quality certificate.
(2) The thickness tolerance should be marked on the product documents when the thickness of the sheet requires accuracy.
7.2 Packaging
(1)The aluminum and aluminum alloy sheets and strips should be carefully packaged to prevent damage to them.
(2) The length, width and thickness of the package should be marked.
7.3 Quality Certificate
The quality certificate should include the following information:
(1) Name of product, variety and standard number;
(2) Manufacturing date;
(3) Results of the appearance and strength tests;
(4) Certificate number;
(5) Manufacturer name or mark.
