GB/T 25715-2010 Sphere nodular cast pipe mold finish machining project

GB/T 25715-2023 Pipe mould for centrifugal ductile iron pipe

GB/T 226-1991 Etch test for macrostructure and defect of steels GB/T 1184-1996 Geometrical tolerancing—Geometrical tolerance for features without individual tolerance indications GB/T 1804-2000 General tolerances for linear and angular dimensions without individual tolerance indications GB/T 5777-1996 Seamless steel pipe and tubing—Methods for ultrasonic testing GB/T 10561-2005 Steel—Determination of content of nonmetallic inclusions—Micrographic method using standards diagrams GB/T 13295-2008 Ductile iron pipes,fittings and accessories for water or gas applications 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 223.11-1991 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 223.18-1994 Methods for chemical analysis of iron, steel and alloy The sodium thiosulfate separation iodimetric method for the determination of cupper content GB/T 223.23-1994 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 223.26-1989 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 223.60-1997 Methods for chemical analysis of iron,steel and alloy—The perchloric acid dehydration gravimetric method for the determination of silicon content GB/T 223.60-2024 Iron,steel and alloy—Determination of silicon content—Gravimetric method GB/T 223.68-1997 Methods for chemical analysis of iron,steel and alloy The potassium iodate titration method after combustion in the pipe furnace for the determination of sulfur content GB/T 223.71-1997 Methods for chemical analysis of iron,steel and alloy—The gravimetric method after combustion in the pipe furnace for the determination of carbon content 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 229-1994 Metallic materials—Charpy notch impact test GB/T 229-2007 Metallic materials—Charpy pendulum impact test method GB/T 229-2020 Metallic materials—Charpy pendulum impact test method 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 20066-2006 Steel and iron—Sampling and preparation of samples for the determination of chemical composition GB/T 223.58-1987 Methods for chemical analysis of iron，steel and alloy--The extraction-absorption catalytic polarographic method for the determination of manganese content GB/T 1979-2001 Standard diagrams for macrostructure and defect of structural steels JB/T 4730.4-2005 Nondestructive testing of pressure equipments—Part 4:Magnetic particle testing GB/T 1979-2025 Evaluation of macrostructural defects in structural steels—Acid etching method and ultrasonic testing method GB/T 223.11-2025 Iron, steel and alloy—Determination of chromium content—Titrimetric method and spectrophotometric method