GB/T 37571-2019 in English

Interpretation of the standard for copper and copper alloy strips for relays

1. Background and significance of the standard

GB/T 37571-2019 "Copper and copper alloy strips for relays" was formulated to meet the demand for high-quality copper and copper alloy strips in relay manufacturing in the field of electronics and electrical engineering. As electronic equipment develops towards high density and miniaturization, the performance requirements for materials are increasing. This standard provides comprehensive technical specifications to ensure the conductivity, mechanical strength and reliability of products.

2. Comparison of standard frameworks

3. Detailed explanation of technical requirements

3.1 Product classification and marking

Strips are classified into T2, TMg0.5, etc. according to grades, and states include 1/2 hard (H02) and hard (H04), with thickness ranging from 0.15 to 2.00 mm and width from 10 to 650 mm. Product marking should include:

• Product name
• Standard number GB/T 37571
• Brand or code
• Status identification
• Specification parameters (such as 0.20×50mm)

3.2 Chemical composition control

The chemical composition must comply with the provisions of GB/T5231 and be tested by spectral analysis or XRF. Focus on monitoring the content of elements such as Cu, Sn, and Fe to ensure material consistency.

3.3 Dimensional deviation

3.4 Mechanical properties test

The strip needs to be subjected to tensile and hardness tests to ensure that the tensile strength and elongation after fracture meet the requirements. For example:

• T2 grade H02 state: Rm≥245MPa, A11.3≥8%
• H65 grade H04 state: Rm≥470MPa, HV≥140

3.5 Bending performance test

The strip needs to be subjected to a 90° bending test, specifying the maximum inner radius and appearance quality. Different grades have different bending requirements according to thickness, such as:

• T2: GW≤1Xt, BW≤1Xt
• H65: GW≥1.0Xt, BW≥1.5Xt

3.6 Electrical performance test

Electrical conductivity is a key indicator, for example, T2 grade ≥97%IACS. The test methods include four-point resistance method and eddy current tester.

4. Implementation suggestions

4.1 Suggestions for manufacturers

• Establish a sound raw material inspection system to ensure stable chemical composition
• Optimize rolling process parameters and control thickness and width deviations
• Equip advanced tensile and hardness testing equipment
• Strengthen surface quality management to avoid scratches and oxidation

4.2 Suggestions for users

• Carry out acceptance inspection strictly in accordance with the standards
• Pay attention to performance fluctuations between batches and conduct full inspection when necessary
• Establish long-term cooperative suppliers to ensure material consistency
• Perform customized tests in special applications

5. Conclusion

GB/T 37571-2019 standard provides comprehensive technical guidance for the production, inspection and application of copper and copper alloy strips for relays. Strict compliance with this standard will help improve product quality and ensure its reliable performance in electronic and electrical equipment.