MT/T 557-1996 Cold-formed square hollow steel for stand-pipe

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 222-2025 Steels and alloys—Permissible deviations of product analyzed chemical composition 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 223.5-1997 Methods for chemical analysis of iron,steel and alloy—The reduced molybdosilicate spectro photometric method for the determination of acid-soluble silicon content GB/T 223.5-2008 Steel and iron—Determination of acid-soluble silicon and total silicon content—Reduced molybdosilicate spectrophotometric method GB/T 223.6-1994 Methods for chemical analysis of iron, steel and alloy—The neutralization titrimetric method for the determination of boron content GB/T 223.6-2025 Iron,steel and alloy—Determination of boron content—Neutralization titrimetric method and spectrophotometric method GB/T 223.7-2002 Iron powder—Determination of iron content—Potassium dichromate titration method GB/T 223.8-2000 Methods for chemical analysis of iron,steel and alloy The sodium fluoride separation—EDTA titration method for the determination of aluminium content GB/T 223.8-2025 Iron,steel and alloy—Determination of aluminium content—Titrimetric method and spectrophotometric method GB/T 223.9-2000 Methods for chemical analysis of iron,steel and alloy The chrom azurol S photometric method for the determination of aluminium content GB/T 223.9-2008 Iron,steel and alloy—Determination of aluminium content—Chrome azurol S photometric method GB/T 223.10-2000 Methods for chemical analysis of iron,steel and alloy The cupferron separation-chrome azurol S photometric method for the determination of aluminium content 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 223.11-2025 Iron, steel and alloy—Determination of chromium content—Titrimetric method and spectrophotometric 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 223.13-2025 Iron,steel and alloy—Determination of vanadium content—Titrimetric method and spectrophotometric method 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/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 GB/T 223.25-1994 Methods for chemical analysis of iron, steel and alloy The dimethylglyoxime gravimetric method for the determination of nickel content GB/T 223.26-1989 Methods for chemical analysis of iron, steel and alloy The thiocyanate direct photometric method for the determination of molybdenum content GB/T 223.26-2008 Iron,steel and alloy—Determination of molybdenum content—The thiocyanate spectrophotometric method GB/T 223.27-1994 Methods for chemical analysis of iron, steel and alloy The thiocyanate-butyl acetate extraction spectrophotometric method for the determination of molybdenum content GB/T 223.28-1989 Methods for chemical analysis of iron, steel and alloy The α-benzoinoxime gravimetric method for the determination of molybdenum content GB/T 223.29-2008 Iron,steel and alloy—Determination of lead content—Carrier precipitation-xylenol orange spectrophotometric method GB/T 223.30-1994 Methods for chemical analysis of iron, steel and alloy The arsenazo Ⅲ spectrophotometric method for the determination of zirconium content after separation by p-bromomandelic acid GB/T 223.31-1994 Methods for chemical analysis of iron, steel and alloy The distillation-molybdenum blue spectrophotometric method for the determination of arsenic content GB/T 223.31-2008 Iron,steel and alloy—Determination of arsenic content—Distillation-molybdenum blue spectrophotometric method GB/T 223.31-2026 Iron, steel and alloy—Determination of arsenic content—Spectrophotometric method and iodimetric method GB/T 223.32-1994 Methods for chemical analysis of iron, steel and alloy The hypophosphite reduction-iodimetric method for the determination of arsenic content GB/T 223.33-1994 Methods for chemical analysis of iron, steel and alloy The chlorophosphonago mA photometric method for the determination of cerium content after extraction separation GB/T 223.34-2000 Methods for chemical analysis of iron,steel and alloy—The determination of hydrochloric acid-insoluble content of iron powders GB/T 223.36-1994 Methods for chemical analysis of iron, steel and alloy The neutral titration method for the determination of nitrogen content after distillation separation GB/T 223.37-1989 Methods for chemical analysis of iron, steel and alloy The indophenol blue photometric method for the determination of nitrogen content after distillation separation GB/T 223.37-2020 Iron,steel and alloy—Determination of nitrogen content—Indophenol blue spectrophotometric method after distillation separation GB/T 223.38-1985 Methods for chemical analysis of iron, steel and alloy—The anion-exchange separation-gravimetric method for the determination of niobium content GB/T 223.78-2000 Methods for chemical analysis of iron,steel and alloy—Curcumin spectrophotometric method for the determination of boron content GB/T 223.79-2007 Iron and steel—Determination of multi-element contents—X-ray fluorescence spectrometry(Routine method) GB/T 223.80-2007 Iron,steel and alloy—Determination of trace bismuth and arsenic contents—Hydride generation-atomic fluorescence spectrometric method GB/T 223.81-2007 Iron,steel and alloy—Determination of total aluminum and total boron contents—Microwave digestion-inductively coupled plasma mass spectrometric method GB/T 223.82-2007 Steel and iron—Determination of hydrogen content—Inert gas impulse fusion heat conductivity method GB/T 223.82-2018 Steel and iron—Determination of hydrogen content—Thermal conductivity/infrared method after fusion under inert gas GB/T 223.83-2009 Steel and iron—Determination of high sulfur content—Infrared absorption method after combustion in an induction furnace GB/T 223.84-2009 Steel and iron—Determination of titanium content—Diantipyrylmethane spectrophotometric method GB/T 223.85-2009 Steel and iron—Determination of sulfur content—Infrared absorption method after combustion in an induction furnace GB/T 223.86-2009 Steel and iron—Determination of total carbon content—Infrared absorption method after combustion in an induction furnace GB/T 223.87-2018 Iron, steel and alloy—Determination of calcium and magnesium—Inductively coupled plasma mass spectrometric method GB/T 223.88-2019 Iron,steel and alloy—Determination of calcium and magnesium contents—Inductively coupled plasma atomic emission spectrometric method GB/T 223.89-2019 Iron,steel and alloy—Determination of tellurium content—Hydride generation-atomic fluorescence spectrometric method GB/T 223.90-2021 Iron,steel and alloy—Determination of silicon content—Inductively coupled plasma atomic emission spectrometric method GB/T 223.91-2021 Iron,steel and alloy—Determination of copper—2,2′-Biquinoline spectrophotometric method GB/T 223.92-2023 Iron, steel and alloy—Determination of lanthanum, cerium, praseodymium, neodymium and samarium content—Inductively coupled plasma mass spectrometry GB/T 228-2002 Metallic materials—Tensile testing at ambient temperature GB/T 228.1-2010 Metallic materials—Tensile testing—Part 1:Method of test at room temperature GB/T 228.1-2021 Metallic materials—Tensile testing—Part 1:Method of test at room temperature GB/T 228.2-2015 Metallic materials—Tensile testing—Part 2:Method of test at elevated temperature GB/T 228.3-2019 Metallic materials—Tensile testing—Part 3:Method of test at low temperature GB/T 228.4-2019 Metallic materials—Tensile testing—Part 4:Method of test in liquid helium GB/T 232-1999 Metallic materials—Bend test GB/T 232-2010 Metallic materials—Bend test GB/T 232-2024 Metallic materials—Bend testing method GB/T 700-1988 Carbon structural steels GB/T 700-2006 Carbon structural steels GB/T 709-1988 Dimensions, shape, weight and tolerances for hot-rolled plates and sheets GB/T 709-2006 Dimension,shape,weight and tolerances for hot-rolled steel plates and sheets GB/T 709-2019 Dimension,shape,weight and tolerance for hot-rolled steel strip,plate and sheet GB/T 2101-1989 General requirements of acceptance, packaging, marking and certification for section steel GB/T 2101-2008 General requirement of acceptance,packaging,marking,and certification for section steel GB/T 2101-2017 General requirement of acceptance,packaging,marking and certification for section steel GB 6397 GB/T 6725-2002 Cold formed steel sections GB/T 6725-2008 Cold forming steel sections GB/T 6725-2017 General requirements of cold forming steel sections GB/T 6728-2002 Cold formed steel hollow sections for general structure—Dimensions,shapes,weight and permissble deviations GB/T 6728-2017 Cold forming hollow sectional steel for general structure GB/T 6728-2025 Cold forming sectional steel for general structure