GB/T 33881-2017Aluminum alloy plats,sheets and strips for tank truck (English PDF)

4.1 Chemical composition

4.1.1 The analytical method for chemical composition shall be as specified in GB/T 20975 or GB/T 7999; and the arbitration analysis shall be conducted in accordance with the method specified in GB/T 20975.

4.1.2 For the designations of 5059, 5088, 5186 and 5383, the routine chemical analysis is only conducted for the values of the elements specified outside the columns "Al" and "other impurities" in Table 2.

4.1.3 The mass fractions of "Al" are calculated in accordance with the method specified in GB/T 3190; when the mass fractions of "Al" is calculated, take the sum of the analytical values of the routine analytical elements and the suspicious excessive non-routine analytical elements as the "total of the mass fractions of elements".

4.1.4 The method of comparing the values rounded off shall be used for the judgement of the analytical values; the rules for the rounding off of values shall be as specified in GB/T 8170; the decimal places rounded off shall be as specified in Table 2 or consistent with the limit places specified in GB/T 3190.

4.2 Dimensional tolerances

The measuring method for the dimensional tolerances shall be as specified in GB/T 3880.3-2012.

4.3 Room-temperature tensile mechanical properties

The method for the test of tensile mechanical properties at room temperature shall be as specified in GB/T 16865.

4.4 Bending properties

The method for the test of bending properties shall be as specified in GB/T 232.

4.5 Appearance quality

Conduct visual inspection for the appearance quality. If necessary, the dimensional measurement tools may be used to define the size of defects and the depth of defects may be measured by repair grinding.

5.1 Inspection and acceptance

5.1.1 Products shall be inspected by the supplier to ensure the quality is as specified than one roll; and take two samples for each roll. Take 2% of the sheet number for each batch of plates and sheets, but not less than two sheets; take one sample by cutting from each sheet sampled.

Appearance quality Conduct inspection on each sheet (or roll) 3.6 4.5

5.6 Judgement of inspection results

5.6.1 When the chemical composition of any sample is unacceptable and the smelting batch can be differentiated, then the smelting batch represented by the sample is unacceptable; and the other smelting batches are subjected to inspection in sequence, which will be delivered if they pass the inspection. When smelting batches are unable to be differentiated, then the lot is judged to be unacceptable.

5.6.2 When the dimensional tolerances of any sample are unacceptable, then the batch is judged to be unacceptable. But inspection on each sheet for plates and sheets is allowed, and those passing the inspection are delivered.

5.6.3 When the room-temperature tensile properties of any sample are unacceptable, then take separately a double number of samples from the batch (or furnace) to repeat the test. If all the results of the repeated test are acceptable, then the batch (or furnace) of products are acceptable. If there is any result of the repeated test still unacceptable, then the batch (or furnace) of products are judged to be unacceptable. When the inspection by the supplier on each sheet (or roll) is allowed as agreed on by the supplier and the purchaser, those passing the inspection are delivered.

5.6.4 When the bending properties of any sample are unacceptable,

5.6.5 When the appearance quality is unacceptable, then the sheet (or roll) is judged to be unacceptable, take separately a double number of samples from the batch (or furnace) of products to repeat the test. If all the results of the repeated test are acceptable, then the batch (or furnace) of products are acceptable. If there is any result of the repeated test still unacceptable, then the batch (or furnace) of products are judged to be unacceptable. When the inspection by the supplier on each sheet (or roll) is allowed as agreed on by the supplier and the purchaser, those passing the inspection are delivered.

6.1 Marking

6.1.1 Product marking

The following marks shall be printed (or labeled) on three sheets each from the lower part and upper part of the pile of plates and sheets which have been approved by […]