www.bzfxw.comwww.bzfxw.comwww.bzfxw.comwww.bzfxw.comwww.bzfxw.comwww.bzfxw.comwww.bzfxw.com
焊接结构用铸钢件Steelcastingsuitableforweldedstructure2010-12-23发布2011-06-01实施ICS77.140.80J31中华人民共和国国家标准GB/T7659—2...