[国外标准] AATCC EP1-2007 Gray Scale for Color Change
[国外标准] AATCC EP1-2005 Gray Scale for Color Change
[国外标准] SAE J431-2000 Automotive Gray Iron Castings
[国外标准] JIS B2031-1994 Gray cast iron valves
[国外标准] JIS G5501-1995 英文版 Gray iron castings