Home / Standards / GB/T 223.37-2020 GB/T 223.37-2020 Active Iron, steel and alloy—Determination of nitrogen content—Indophenol blue spectrophotometric method after distillation separation 钢铁及合金 氮含量的测定 蒸馏分离靛酚蓝分光光度法 Standard Type GBT ICS 77.080.01 CCS H11 Status 现行 Issue Date 2020-06-02 Implementation 2021-01-01 Responsible Dept 中国钢铁工业协会 Drafting Unit N/A