Home / Standards / GB/T 20509 GB/T 20509 Active Copper and copper alloys drawing for contacting materials of electric locomotives 电力机车接触材料用铜及铜合金线坯 Standard Type GBT ICS 77.150.30 CCS H62 Status 现行 Issue Date 2023-05-23 Implementation 2023-12-01 Responsible Dept 中国有色金属工业协会 Drafting Unit 中国有色金属工业协会