[国外标准] SAE J1975-1997 CASE HARDENABILITY OF CARBURIZED STEELS
[国外标准] BS EN 10084-2008 Case hardening steels - Technical delivery conditions
[国外标准] JIS G7503-2000 Wrought case-hardening steels
[国外标准] JIS X6244-1998 Case for 120 mm DVD-RAM Disks