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GB/T 34560 consists of the following six parts under the general title Structural steels:
——Part 1: General technical delivery condition for hot-rolled products;
——Part 2: Technical delivery conditions for structural steels for general purposes;
——Part 3: Technical delivery conditions for fine grain structural steels;
——Part 4: Technical delivery conditions for high yield strength quenched and tempered structural steel plates;
——Part 5: Technical delivery condition for atmospheric corrosion resisting steels;
——Part 6: Technical delivery conditions for seismic-improved structural steels for building.
This part is Part 2 of GB/T 34560.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
In this part, ISO 630-2: 2011 Structural steels - Part 2: Technical delivery conditions for structural steels for general purposes was revised and adopted by redrawing method.
This part is changed from ISO 630-2: 2011 in structure; the comparison table for clause numbers of this standard and ISO 630-2: 2011 is listed in Annex A.
This part includes technical changes with respect to ISO 630-2: 2011. The clause and subclause concerned are identified by a vertical single line (|) located in the blank on its external margin of the page. These technical changes and reasons are listed in Annex B.
The following editorial changes present in this part:
——The bibliography in ISO 630-2: 2011 has been deleted;
——The Annex D (informative) has been added;
This part was proposed by China Iron and Steel Association.
This part is under the jurisdiction of the SAC/TC 183 National Technical Committee on Iron and Steel of Standardization Administration of China.
Structural steels -
Part2: Technical delivery conditions for structural steels for general purposes
1 Scope
This part of GB/T 34560 specifies the terms and definitions, classification and designation expression methods, order details, dimensions, shape, mass, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of structural steels for general purposes.
This part is applicable to hot rolled steel plate (strip), wide flat steel, profile steel and steel bar (hereinafter referred to as "steel") for general welding, bolting and riveting engineering structures.
The chemical composition specified in this part is also applicable to steel ingots, continuous casting slabs, billets and their products.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 222 Permissible tolerances for chemical composition of steel products
GB/T 223.3 Methods forchemical analysis of iron, steel and alloy - The diantipyryl methane phosphomolybdate gravimetric method for the determination of phosphorus content
GB/T 223.9 Iron, steel and alloy - Determination of aluminum content - Chrom azurol S photometric method
GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration method (GB/T 223.11.2008-2008, ISO 4937: 1986, MOD)
GB/T 223.14 Methods for chemical analysis of iron, steel and alloy - The n-benzoyl-n-phenylhydroxylamine extraction photometric method for the determination of vanadium
GB/T 223.17 Methods for chemical analysis of iron, steel and alloy - The Diantipyrylmethane photometric method for the determination of titanium content
GB/T 223.18 Methods for chemical analysis of iron, steel and alloy - The sodium thiosulfate separation iodimetric method for the determination of copper content
GB/T 223.23 Iron steel and alloy - Determination of nickel content - The dimethylglyoxime spectrophotometric method
GB/T 223.26 Iron steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method
GB/T 223.37 Methods for chemical analysis of iron, steel and alloy - The indophenal blue photometric methods for the determination of nitrogen content after distillation separation
GB/T 223.40 Iron steel and alloy - determination of niobium content by the sulphochlorophenol S spectrophotometric method
GB/T 223.60 Methods for chemical analysis of iron, steel and alloy - The perchloric acid dehydration gravimetric method for the determination of silicon content
GB/T 223.63 Methods for chemical analysis of iron, steel and alloy - The sodium (potassium) periodate photometric method for the determination of manganese content
GB/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 determination of sulfur content
GB/T 223.69 Iron, steel and alloy - Determination of carbon contents - Gas-volumetric method after combustion in the pipe furnace
GB/T 223.76 Methods for chemical analysis of iron, steel and alloy The flame atomic absorption spectrometric method for the determination of vanadium content
GB/T 223.77 Methods for chemical analysis of iron, steel and alloy The flame atomic absorption spectrometric method for the determination of vanadium content
GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room temperature (GB/T 228.1-2010; ISO 6892-1:2009, MOD)
GB/T 229 Metallic materials - Charpy pendulum impact test method (GB/T 229-2007, ISO 148-1:2006, MOD)
GB/T 232 Metallic materials - Bend test (GB/T 232-2010; ISO 7438: 2005, MOD)
GB/T 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 2101 General requirements of acceptance, packaging, marking,and certification for section steel
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing (GB/T 2975-1998; eqv ISO 377: 1997)
GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (routine method)
GB/T 5313 Steel plates with through-thickness characteristics
GB/T 13304.1 Steels classification - Part 1: Classification of according to chemical composition (GB/T 13304.1-2008; ISO 4948-1: 1982, MOD)
GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition (GB/T 20066-2006; ISO 14284: 1996, IDT)
GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method) (GB/T 20123-2006; ISO 15350:2000, IDT)
GB/T 34560.1 Structural steels - Part 1: General technical delivery condition for hot-rolled products (GB/T 34560.1-2017; ISO 630-1: 2011, MOD)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 34560.1 apply.
4 Classification and designation expression methods
4.1 According to the classification of GB/T 13304.1, the steels specified in this part shall be classified as non-alloy and low-alloy steel.
4.2 The steel designation is composed of three parts: Q (the Chinese phonetic alphabet representing yield strength); the specified minimum upper yield strength; quality grade symbol (A, B, C and D).
Example:
Q355D, where:
Q——the Chinese phonetic alphabet representing yield strength;
4.3 Where the purchaser asks the steel plate to be provided with through-thickness property (Z direction), the grade in through-thickness property shall be added after the above-mentioned designation, e.g. Q355DZ25.
5 Order contents
5.1 Contracts or orders made based on this part shall cover the following items:
a) Standard No.;
b) Product type;
c) Steel grade + delivery condition + quality grade;
d) Dimension, shape and permissible deviation;
e) All selected contents as required.
f) Types of inspection documents.
5.2 For the purpose of this part, the following contents may be selected for order through negotiation between the supplier and the purchaser as indicated in the contract. If not specified by the purchaser upon inquiry and order, products shall be supplied according to 5.1.
a) smelting method;
b) finished product analysis;
c) calculation formula of carbon equivalent value (CEV) or welding crack susceptibility index (Pcm);
d) mechanical properties after additional heat treatment;
e) through-thickness property;
f) bending properties;
g) methods for chemical analysis;
h) test frequency;
i) orientation of impact test specimen;
j) packaging and marking;
k) the appropriate hot galvanizing method agreed upon under relevant standards;
l) non-destructive inspection agreed upon under relevant standards.
6 Dimensions, shape and mass
The dimension, shape, mass and tolerance of the steel shall meet those specified in GB/T 34560.1.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Classification and designation expression methods 5 Order contents 6 Dimensions, shape and mass 7 Technical requirements 8 Test method 9 Inspection rules 10 Packaging, marking and quality certificate Annex A (Informative) Structural changes of this part with respect to ISO 630-2: Annex B (Informative) Technical differences between this part and ISO 630-2: 2011 and their causes Annex C (Normative) Technical requirements for steels Q390, Q420 and Q Annex D (Informative) Cross reference between designations in standards at home and abroad
注：国内外标准牌号对照参见附录D。 a 公称厚度大于100mm 的型钢，碳含量由供需双方协商确定。 b 经供需双方协商，碳含量可不大于0.22%。 c 型钢和棒材，磷和硫含量可提高0.005%。 d 型钢和棒材，为改善机加工性能，如对钢进行处理以改变硫化物的形态，经供需双方协商，硫含量最大值可增加0.015%，钙含量可不小于0.0020%。 e 公称厚度大于150mm 的钢材，碳含量不大于0.20%。 f 公称厚度大于30mm 的钢材，碳含量不大于0.22%。 g 仅适用于型钢和棒材产品。 h 钢中铌、钒、钛含量分别不大于0.05%、0.13%和0.05%。
a 当需对Q275和Q355中Si含量控制时(例如热浸镀锌涂层)，为了满足抗拉强度要求，需增加其他元素，如碳和锰，此时表中最大碳当量的值增加应符合以下规定： 硅含量不大于0.030%时，碳当量可提高0.02%； 硅含量不大于0.25%时，CEV可提高0.01%。 b 对于型钢和棒材，最大碳当量允许值为0.54%。 c 仅适用于型钢和棒材。
表3上屈服强度和抗拉强度 钢级 质量 等级 上屈服强度ReH/MPa 不小于 抗拉强度Rma/MPa 公称厚度(或直径) ≤16 mm >16 mm ～40 mm >40 mm ～63 mm >63 mm ～80 mm >80 mm ～100 mm >100 mm ～150 mm >150 mm ～200 mm >200 mm～250mm >250mm～400mmb <3mm >3 mm ～100 mm >100 mm ～150 mm >150 mm ～250 mm >250 mm ～400 mmb
a 公称厚度不大于12mm 或公称直径不小于16mm 的钢材应符合GB/T 34560.1的规定。 b 公称厚度大于100mm 的型钢，冲击吸收能量由供需双方协商确定。 c 适用于扁平材。 d 仅适用于棒材。
表6 弯曲试验 钢级 试样方向 180°弯曲试验 (D =弯曲压头直径，a=试样厚度或直径) 公称厚度(或直径) ≤16mm >16mm~60mm >60mm~100mm Q235 宽度不小于600mm 扁平材，取横向试样；宽度小于600mm 的扁平材、型材及棒材取纵向试样 D =a D =2a Q275 D =1.5a D =2.5a Q355 D =2a D =3a Q450
附 录 C (规范性附录) Q390、Q420和Q460钢级的技术要求 C.1 化学成分 Q390、Q420和Q460钢级的化学成分(熔炼分析)应符合表C.1的规定。 表C.1 化学成分 钢级 质量 等级 化学成分(质量分数)／% Ca Si Mn P S Cr Ni Cu Nb V Ti Mo N H 不大于
a 对于厚度大于100mm 的型钢，碳含量可协议规定。 b 对Q390钢级的型材或棒材，磷和硫含量上限可提高0.005%。 c 仅适用于棒材。
