GB/T 18880-2012Materials for bonded neodymium iron boron permanent magnets (English PDF)

7.1 Inspection and acceptance

7.1.1 Products are inspected by the supplier's quality and technical supervision department. Ensure product quality complies with the provisions of this standard. Fill out the quality certificate.

7.1.2 The purchaser shall inspect the received products in accordance with the provisions of this Standard. If the inspection results are inconsistent with the provisions of this Standard, it shall be reported to the supplier within 1 month from the date of receipt of the product. The matter shall be resolved through negotiation between the supplier and the purchaser. If arbitration is needed, an agency recognized by both parties can be entrusted to conduct it, and samples can be taken jointly by the purchaser.

7.2 Batching Each batch of products shall be composed of materials of the same specifications and sizes made by the same designation and the same production process.

7.3 Inspection items Each batch of products shall be inspected for magnetic properties, dimensional tolerances, geometric tolerances, appearance quality and other items. The sampling batches, methods, quantities, anti-rust performance index items and qualified quality levels for anti-rust performance inspection shall be agreed upon by both parties. When the anti-rust coating materials and processes are changed, inspections shall be carried out according to the anti-rust performance index items and qualified quality levels agreed between the supplier and the purchaser.

7.4 Sampling The sampling quantity of the magnetic properties, dimensional tolerance, and geometric tolerance of the product shall be carried out in accordance with the provisions of GB/T 2828. Its acceptance qualified quality level (AQL) is level

1.5 of general inspection level II. The sampling quantity of product appearance quality shall be carried out in accordance with the provisions of GB/T 2828. Its acceptance quality level (AQL) is level

1.5 of general inspection level I. All are carried out according to a normal inspection sampling plan. The principal magnetic properties of the material and the anti-rust performance of the product shall be determined by sampling quantity and qualified quality level as agreed upon by both parties.

7.5 Inspection result judgment If the product's principal magnetic properties or anti-rust properties, dimensional tolerances, geometric tolerances, appearance quality and other inspection results are inconsistent with the provisions of this Standard, double samples will be taken from the batch of products to re-inspect the unqualified items. If there are still unqualified items, the batch of products will be judged as unqualified.

8.1 Marks, packaging

8.1.1 If the purchaser requires the polarity of the product to be marked, it can be clearly stipulated in the contract.

8.1.2 Product packaging shall comply with the corresponding regulations on transportation and storage methods. Generally, foam plastic boxes are used as inner packaging. The outer packaging is in cartons or wooden boxes. Guarantee against damage during proper transportation and storage. Each outer packaging shall be marked with a mark on its surface, indicating:

a) Name of supplier;

b) Product name;

c) Batch number, specification size or product code;

d) Quantity, gross weight, exit-factory date.

8.2 Transportation, storage In the constant temperature and humidity standard test chamber, put the coated product specimen. Store at 90% relative humidity and 80°C ±1°C test temperature for 240 h. After taking it out, place it at 23°C±3°C for 2 h. Use a 10x magnifying glass to observe the coating surface of the specimen. If there is no rust or expansion phenomenon, it will be judged as qualified. A.2.4 Acid resistance test Put 10 mL of hydrochloric acid [(1+2), chemically pure] into a cleaned 200 mL plastic bottle. Then add 60 mL of laboratory grade 3 water to prepare hydrochloric acid (1+19). Then put in the coated product specimen. Cover and leave for 24 h. Then take out the product specimen. After cleaning, dry at 23°C ±3°C for 2 h. Observe with a 10x magnifying glass. When the coating film of the specimen (except for the electrode contacts during coating) does not have swelling, cracking, peeling, bubbles, softening, dissolution, and no major changes in color and brightness, it is judged to be qualified. A.2.5 Salt spray resistance test In the salt spray standard test chamber, put the painted product specimen. The main conditions for the test must comply with the requirements of GB/T 2423.17 and GB/T 2423.18. The specimen can be properly cleaned before testing. However, abrasives and solvents with corrosive or inhibitory effects cannot be used for cleaning. The cleaning method must not damage the surface. After cleaning the specimen, wipe it dry with a clean cloth or absorbent paper, or blow it dry with oil-free dry air. Handprint contamination will cause serious adverse test results, so the specimen must not have any handprint contamination after cleaning. After the salt spray test is completed, the specimen is taken out and placed at 23°C ±3°C for 2 h. Observe with a 10x magnifying glass. When the coating film of the specimen (except for the electrode contacts during coating) does not have swelling, cracking, peeling, bubbles, softening, dissolution, and no major changes in color and brightness, it is judged to be qualified. A.2.6 Adhesion tape peeling test Fix the coated product specimen on the table. Use a single-sided cutting blade to mark the "#" shape. Be sure to use the tip of the knife when cutting into the knife mark. Opposite the coating surface, the tip of the knife is perpendicular to the coating surface and penetrates the coating film. The intervals between each cut are about 1 mm. Then stick the 3M600 tape on the product specimen marked with the character "#". Lift up one end of the tape and pull instantly. If there is no defect in the coating film, it will be judged as qualified.