GB/T 13793-1992 Longitudinal electric resistance welded steel tubes

GB/T 13793-2008 Steel pipes with a longitudinal electric (resistance) weld

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

JIS G3444-1988