Home / Standards / GB/T 7216-1987 GB/T 7216-1987 Abolished Gray cast iron metallography 灰铸铁金相 Standard Type GBT ICS 77.040.30 CCS J31 Status 废止 Issue Date 1987-01-24 Implementation 1987-10-01 Responsible Dept 国家标准委 Drafting Unit N/A