Home / Standards / GB/T 7731.1-2021 GB/T 7731.1-2021 Active Ferrotungsten—Determination of tungsten content—Cinchonine gravimetric method and ammonium nitrate gravimetric method 钨铁 钨含量的测定 辛可宁重量法和硝酸铵重量法 Standard Type GBT ICS 77.100 CCS H11 Status 现行 Issue Date 2021-08-20 Implementation 2022-03-01 Responsible Dept 中国钢铁工业协会 Drafting Unit N/A