Home / Standards / GB/T 7731.1-1987 GB/T 7731.1-1987 Abolished Methods for chemical analysis of ferrotungsten--The cinchonine gravimetric method for the determination of tungsten content 钨铁化学分析方法 辛可宁重量法测定钨量 Standard Type GBT ICS 77.100 CCS H11 Status 废止 Issue Date 1987-05-12 Implementation 1988-03-01 Responsible Dept 中国钢铁工业协会 Drafting Unit N/A