GB/T 11880-1989 Large die-blocks used for die-forging hammer and mechanical forging press—Specification

GB/T 11880-2008 Specification of large die-blocks used for die-forging hammer and mechanical forging press

GB 223.1~223.4 GB 223.1~223.4 GB/T 223.3-1988 Methods for chemical analysis of iron, steel and alloy—The diantipyryl methane phosphomolybdate gravimetric method for the determination of phosphorus content GB/T 223.4-1988 Methods for chemical analysis of iron, steel and alloy The volumetric method for determination of manganese content by ammonium nitrate oxidation GB/T 223.4-2008 Alloyed steel—Determination of manganese content—Potentiometric or visual titration method GB/T 223.11-1991 Methods for chemical analysis of iron, steel and alloy The ammonium persulfate oxidation volumetric method for the determination of chromium content GB/T 223.11-2008 Iron,steel and alloy—Determination of chromium content—Visual titration or potentiometric titration method GB/T 223.12-1991 Methods for chemical analysis of iron, steel and alloy—The sodium carbonate separation-diphenyl carbazide photometric method for the determination of chromium content GB/T 223.13-2000 Methods for chemical analysis of iron,steel and alloy The ammonium ferrous sulfate titration method for the determination of vanadium content GB/T 223.14-2000 Methods for chemical analysis of iron,steel and alloy The N-benzoy-N-phenylhydroxylamine extraction photometric method for the determination of vanadium content GB 223.11~223.24 GB/T 223.16-1991 Methods for chemical analysis of iron, steel and alloy—The chromotropic acid photometric method for the determination of titanium content GB/T 223.17-1989 Methods for chemical analysis of iron, steel and alloy The diantipyrylmethane photometric method for the determination of titanium content GB/T 223.18-1994 Methods for chemical analysis of iron, steel and alloy The sodium thiosulfate separation iodimetric method for the determination of cupper content GB/T 223.19-1989 Methods for chemical analysis of iron, steel and alloy The neocuproine-chloroform extraction photometric method for the determination of copper content GB/T 223.20-1994 Methods for chemical analysis of iron,steel and alloy The potentiometric titration method for the determination of cobalt content GB/T 223.21-1994 Methods for chemical analysis of iron, steel and alloy The 5-Cl-PADAB spectrophotometric method for the determination of cobalt content GB/T 223.22-1994 Methods for chemical analysis of iron, steel and alloy The nitroso-R-salt spectrophotometric method for the determination of cobalt content GB/T 223.23-1994 Methods for chemical analysis of iron, steel and alloy—The dimethylglyoxime spectrophotometric method for the determination of nickel content GB/T 223.23-2008 Iron,steel and alloy—Determination of nickel content—The dimethylglyoxime spectrophotometric method GB/T 223.24-1994 Methods for chemical analysis of iron, steel and alloy The extraction separation—The dimethylglyoxime spectrophotometric method for the determination of nickel content YB 35(12) YB 25 GB/T 222-1984 Method of sampling steel for determination of chemical composition and permissible variations for product analysis GB/T 222-2006 Permissible tolerances for chemical composition of steel products GB/T 231.1-2002 Metallic materials—Brinell hardness test—Part 1:Test method GB/T 231.1-2009 Metallic materials—Brinell hardness test—Part 1:Test method GB/T 231.1-2018 Metallic materials—Brinell hardness test—Part 1:Test method GB/T 231.2-2002 Metallic Brinell hardness test—Part 2:Verification and calibration of hardness testers GB/T 231.2-2012 Metallic materials—Brinell hardness test—Part 2:Verification and calibration of testing machines GB/T 231.2-2022 Metallic materials—Brinell hardness test—Part 2:Verification and calibration of testing machines GB/T 231.3-2002 Metallic Brinell hardness test—Part 3:Calibration of hardness reference blocks GB/T 231.3-2012 Metallic materials—Brinell hardness test—Part 3:Calibration of reference blocks GB/T 231.3-2022 Metallic materials—Brinell hardness test—Part 3:Calibration of reference blocks GB/T 231.4-2009 Metallic materials—Brinell hardness test—Part 4:Tables of hardness values GB/T 222-2025 Steels and alloys—Permissible deviations of product analyzed chemical composition GB/T 223.11-2025 Iron, steel and alloy—Determination of chromium content—Titrimetric method and spectrophotometric method GB/T 223.13-2025 Iron,steel and alloy—Determination of vanadium content—Titrimetric method and spectrophotometric method