ICS 77.140.45
H 40
National standard of the People's Republic of China世纪宝鼎
GB/T 700-2006
描写生活的句子 Replace GB/T 700-1988
碳素结构钢
Carbon structural steels
(ISO 630:1995, Structural steels –
Plates, wide flats, bars, ctions and profiles, NEQ)
Issue date: Nov 1, 2006 Implementation date: Feb 1, 2007
Issued by: General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China
Standardization Administration of the People's Republic of China (SAC)
Foreword
This standard is not equivalent to ISO 630:1995 Structural Steels in the respect of consistency. The main differences between 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;月食形成的原因
-The phosphorus contents of class A steels of Q235 and Q275 are decread by 0.005%;邮箱的英文
The 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 connt of the buyer if the supplier can ensure that the impact absorbed energy is up to standard;
-The yield strength of Q275 steel of which the thickness is bigger than 80mm~100mm is incread 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 Structural Steels and has the following changes in comparison with GB/T 700-1988:
-Semi-killed steel is cancelled in “deoxidization method”;
读书简笔画
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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 and mangane contents of each grade are cancelled, and the upper limit of mangane content is incread;
-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 Q195 are decread 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 ud as a term of delivery” and “Q235 class B steel of which the thickness is smalle
r than 25mm may not be subject to test with the connt 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 nitrogen 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” and the limitation for the furnace number of mixed batch is cancelled.
Annex A of this standard is normative.
This standard was propod by China Iron and Steel Association.
This standard is under the jurisdiction of National Technical Committee for Steel Standardization.
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This standard was drafted by China 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 in January 1965, first revid in October 1979 and revid for the cond time in June 1988.
Carbon structural steels
芹菜鱿鱼
1 Scope
This standard specifies the grade, dimension, shape, weight and permissible deviation, technical requirements, test methods, inspection rules, packing, marking and quality certificate of carbon structural steel.
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This standard is applicable to the structural hot rolled steel sheets, steel strips, ctional steels and bar steels generally ud for welding, riveting and bolting engineering in delivery state.
The chemical composition specified by this standard is also applicable to steel ingots, continuous casting billets, steel billets and their products.
2 Normative references
The following normative documents contain provisions which, through reference in this text，constitute provisions of this standard. For dated references, subquent amendments (not including corrections) to, or revisions of, any of the publications do not apply. However parties to agreements bad 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 normative document referred to applies.
