GBT碳素结构钢EN.docx

1、GBT碳素结构钢ENICS 77.140.45H 40National standard of the Peoples Republic of ChinaGB/T 700-2006 Replace GB/T 700-1988碳素结构钢Carbon structural steels(ISO 630:1995, Structural steels Plates, wide flats, bars, sections and profiles, NEQ)Issue date: Nov 1, 2006 Implementation date: Feb 1, 2007Issued by: Genera

2、l Administration of Quality Supervision, Inspection and Quarantine of the Peoples Republic of ChinaStandardization Administration of the Peoples Republic of China (SAC)ForewordThis standard is not equivalent to ISO 630:1995 Structural Steels in the respect of consistency. The main differences betwee

3、n the two standards are as follows:- No grades are specified corresponding to the yield strength levels of 185N/mm2 and 355N/mm2;- Grades Q195 and Q215 are specified corresponding to levels 195N/mm2 and 215N/mm2;- The phosphorus contents of class A steels of Q235 and Q275 are decreased by 0.005%;The

4、 thickness of Q235 class B steel is divided into two levels according to the deoxidization method and the carbon content is 0.20% in both levels;- Q235 class B steel of which the thickness is smaller than 25mm may not be subject to test with the consent of the buyer if the supplier can ensure that t

5、he impact absorbed energy is up to standard;- The yield strength of Q275 steel of which the thickness is bigger than 80mm100mm is increased by 10N/mm2;- Cold bending test is added;- Detailed batching rules are specified according to the situation of China.This standard replaces GB/T 700-1988 Carbon

6、Structural Steels and has the following changes in comparison with GB/T 700-1988:- Semi-killed steel is cancelled in “deoxidization method”;- Grades Q255 and Q275 in GB/T 700-1988 are cancelled;- Grade E275 in ISO 630:1995 is newly added and changed to the new grade Q275;- The lower limits of carbon

7、 and manganese contents of each grade are cancelled, and the upper limit of manganese content is increased;- The limit of silicon content of rimmed steel and killed steel is cancelled;- silicon content is changed from 0.30% to 0.35% (except for Q195);- The phosphorus and sulphur contents of grade Q1

8、95 are decreased respectively from 0.045% and 0.050% to 0.035% and 0.040%;- The regulation for the elongation after fracture of the thickness (or diameter) level of not bigger than 16mm is cancelled;- “The upper limit of the tensile strength of wide strip steel (including sheared steel plate) is not

9、 used as a term of delivery” and “Q235 class B steel of which the thickness is smaller than 25mm may not be subject to test with the consent of the buyer if the supplier can ensure that the impact absorbed energy is up to standard” are added in the footnotes of Table 2;- The regulation for the nitro

10、gen content in the steel is modified;- The regulation for impact test is modified and the figure of the minimum impact absorbed energy of the samples of which the thickness is 5mm-10mm is added;- The basis of batching is changed from “the same furnace and kettle number” to “the same furnace number”

11、and the limitation for the furnace number of mixed batch is cancelled.Annex A of this standard is normative.This standard was proposed by China Iron and Steel Association.This standard is under the jurisdiction of National Technical Committee for Steel Standardization.This standard was drafted by Ch

12、ina Metallurgical Information & Standardization Institute, Capital Iron and Steel Company, Handan Iron & Steel Group and Benxi Iron & Steel Group Co., Ltd.The main drafters of this standard are Tang Yifan, Luan Yan, Wang Liping, Sun Ping, Zhang Xianfeng and Dai Qiang.This standard was first issued i

13、n January 1965, first revised in October 1979 and revised for the second time in June 1988.Carbon structural steels1 ScopeThis standard specifies the grade, dimension, shape, weight and permissible deviation, technical requirements, test methods, inspection rules, packing, marking and quality certif

14、icate of carbon structural steel.This standard is applicable to the structural hot rolled steel sheets, steel strips, sectional steels and bar steels generally used for welding, riveting and bolting engineering in delivery state.The chemical composition specified by this standard is also applicable

15、to steel ingots, continuous casting billets, steel billets and their products.2 Normative referencesThe following normative documents contain provisions which, through reference in this text，constitute provisions of this standard. For dated references, subsequent amendments (not including correction

16、s) to, or revisions of, any of these publications do not apply. However parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normat

17、ive document referred to applies.GB/T 222-2006 Permissible tolerances for chemical composition of steel productsGB/T 223.3 Methods for chemical analysis of iron, steel and alloy-The diantipyryl methane phosphomolybdate gravimetric method for the determination of phosphorus contentGB/T 223.10 Methods

18、 for chemical analysis of iron, steel and alloy-The cupferron separation-chrome azurol S photometric method for the determination of aluminum contentGB/T 223.11 Methods for chemical analysis of iron, steel and alloy-The ammonium persulfate oxidation volumetric method for the determination of chromiu

19、m contentGB/T 223.18 Methods for chemical analysis of iron, steel and alloy-The sodium thiosulfate separation iodimetric method for the determination of copper contentGB/T 223.19 Methods for chemical analysis of iron, steel and alloy-The neocuproine-chloroform extraction photometric method for the d

20、etermination of copper contentGB/T 223.24 Methods for chemical analysis of iron, steel and alloy-The extraction separation-dimethylglyoxime spectrophotometric method for the determination of nickel contentGB/T 223.32 Methods for chemical analysis of iron, steel and alloy-The hypophosphite reduction-

21、iodimetric method for the determination of arsenic contentGB/T 223.37 Methods for chemical analysis of iron, steel and alloy-The indophenol blue photometric method for the determination of nitrogen content after distillation separationGB/T 223.58 Methods for chemical analysis of iron, steel and allo

22、y-The sodium arsenite-sodium nitrite titrimetric method for the determination of manganese contentGB/T 223.59 Methods for chemical analysis of iron,steel and alloy-The reduced molybdoantimonyl phosphoric acid photometric method for the determination of phosphorus contentGB/T 223.60 Methods for chemi

23、cal analysis of iron, steel and alloy-The perchloric acid dehydration gravimetric method for the determination of silicon contentGB/T 223.63 Methods for chemical analysis of iron, steel and alloy-The sodium (potassium) periodate photometric method for the determination of manganese contentGB/T 223.6

24、4 Methods for chemical analysis of iron, steel and alloy-The flame atomic absorption spectrometric method for the determination of manganese contentGB/T 223.68 Methods for chemical analysis of iron, steel and alloy-The potassium iodate titration method after combustion in the pipe furnace for the de

25、termination of sulfur contentGB/T 223.71 Methods for chemical analysis of iron, steel and alloy-The gravimetric method after combustion in the pipe furnace for the determination of carbon contentGB/T 223.72 Methods for chemical analysis of iron, steel and alloyThe alumina chromatographic separation-

26、barium sulfate gravimetric method for the determination of sulphur contentGB/T 228 Metallic materials - Tensile testing at ambient temperature (GB/T 228-2002, eqv ISO 6892:1998)GB/T 229 Metallic materials - Charpy notch impact test (GB/T 229-1994, eqv ISO 83:1976, eqv ISO 148:1983)GB/T 232 Metallic

27、materials-Bend test (GB/T 232-1999, eqv ISO 7438:1985)GB/T 247 General rule of acceptance, package, mark and certification for steel plates (sheets) and stripsGB/T 2101 General regulation of the checkout, package, mark and quality certificate of profiled barGB/T 2975 Steel and steel products Locatio

28、n and preparation of test pieces for mechanical testing (GB/T 2975-1998, eqv ISO 377:1997)GB/T 4336 Standard test method for spark discharge atomic emission spectrometric analysis of carbon and low-alloy steel (routine method)GB/T 20066 Steel and iron-Sampling and preparation of samples for the dete

29、rmination of chemical composition (GB/T 20066-2006, ISO 14284:1996, IDT)3 Denotation of the grade and symbols3.1 Denotation of the gradeThe grade of steel is composed of the letter representing yield strength, value of yield strength, symbol of quality grade and symbol of deoxidization method in tur

30、n. For example: Q235AF.3.2 SymbolsQ- First letter of Chinese phonetic spelling for the “Qu” word of steel yield strength;A, B, C, D-are respectively quality grade;F- First letter of Chinese phonetic spelling for the “Fei” word of rimmed steel;Z- First letter of Chinese phonetic spelling for the “Zhe

31、n” word of killed steel;TZ- First letters of Chinese spelling for the “Tezhen” word of special killed steel.In the denotation of grade components, symbols “Z” and “TZ” can be omitted.4 Dimension, shape, weight and permissible deviationThe dimension, shape, weight and permissible deviation of steel s

32、heets, steel strips, sectional steels and bar steels shall meet the specification of the corresponding standards respectively.5 Technical requirements 5.1 Grade and chemical composition5.1.1 The grade and chemical composition (smelting analysis) of the steel shall conform to Table 1.Table 1GradeUnified Numerical CodeaClassThickness (or Diameter)/mmDeoxidization MetodChemical Composition (Mass Percentage)/%, not higher thanCSiMnPSQ195U11952-F,Z0.120.300