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GB/T 1499.2-2018 English 300 Add to Cart 0--15 minutes. Auto immediate delivery. Steel for the reinforcement of concrete--Part 2: Hot rolled ribbed bars Valid GB/T 1499.2-2018
GB/T 1499.2-2018 Chinese 19 Add to Cart <=1-day [PDF from Chinese Authority, or Standard Committee, or Publishing House]
Detail Information of GB/T 1499.2-2018; GB/T1499.2-2018
Description (Translated English): Steel for the reinforcement of concrete--Part 2: Hot rolled ribbed bars
Word Count Estimation: 26,232
Date of Implementation: 2018-11-01
Drafting Organization: China Metallurgical Building Research Institute Co., Ltd., Metallurgical Industry Information Standards Institute, Shougang Changzhi Steel Co., Ltd., Shandong Iron and Steel Co., Ltd. Laiwu Branch, Jiangsu Shagang Group Co., Ltd., Wuhan Iron and Steel Group Kunming Iron and Steel Co., Ltd., Fujian Sansteel ( (Group) Co., Ltd., Jigang Group Co., Ltd., Jiangsu Yonggang Group Co., Ltd., Hebei Jinxi Iron & Steel Group Co., Ltd., Hebei Jingye Iron & Steel Co., Ltd., Zhongtian Iron & Steel Group Co., Ltd., Jiangsu Shente Iron & Steel Co., Ltd., Fushun New Steel Limited liability company, Tangshan Donghua Iron and Steel Enterprise Group Co., Ltd., Jiangsu Xinxin Iron & Steel Group Co., Ltd., and Iron and Steel Research Institute
Steel for the reinforcement of concrete-Part 2. Hot rolled ribbed bars
Replace GB/T 1499.2-2007
Part 2. Hot rolled ribbed bars
Steelforthereinforcementofconcrete-
Part 2.Hotroledribbedbars
(ISO 6935-2.2015, Steelforthereinforcementofconcrete-
Part 2. Ribbedbars, NEQ)
2018-11-01 implementation
4 classification, grade 3
5 Ordering content 3
6 Dimensions, shape, weight and tolerance 3
6.1 Nominal diameter range 3
6.2 Nominal cross-sectional area and theoretical weight 3
6.3 Reinforcement surface shape and size tolerance 4
6.4 Length and tolerance 7
6.5 Bending and end 7
6.6 Weight and tolerance 7
7 Technical requirements 7
7.1 Smelting method 7
7.2 Grades and Chemical Composition 7
7.3 Delivery Type 8
7.4 Mechanical properties 8
7.5 Process performance 9
7.6 Fatigue performance 10
7.7 Connection performance 10
7.8 grain size 10
7.9 Metallographic organization 10
7.10 Surface quality 10
8 Test method 10
8.1 Inspection item 10
8.2 Tensile, bending, reverse bending test 11
8.3 Dimensional measurement 11
8.4 Measurement of weight deviation 12
8.5 Macroscopic metallographic, cross-section Vickers hardness, microstructure inspection 12
8.6 Numerical repair 12
9 Inspection rules 12
9.1 Inspection classification 12
9.2 Characteristic value test 12
9.3 Delivery inspection 12
10 Packaging, Marking and Quality Certificate 13
Appendix A (informative appendix) Formula for calculating the relative rib area of steel bars 14
Appendix B (normative appendix) Macroscopic metallographic, cross-section Vickers hardness, microstructure and test methods for steel bars 15
Appendix C (Normative Appendix) Eigenvalue Test Rule 18
GB/T 1499 "Steel for reinforced concrete" is divided into three parts.
--- Part 1. Hot rolled round bars;
--- Part 2. Hot rolled ribbed steel;
--- Part 3. Steel welded mesh.
This part is the second part of GB/T 1499.
This part replaces GB/T 1499.2-2007 "Steel for reinforced concrete Part 2. Hot-rolled ribbed steel bars".
Compared with GB/T 1499.2-2007, the main changes in this section are as follows.
--- Increased smelting methods;
--- Cancel the 335MPa grade steel bar;
--- Added 600MPa grade steel bar;
--- Increased the number of steel bars with E;
--- Appropriate tolerance for length tolerance and bending;
--- Appropriate tightening of the weight tolerance, clear weight deviation is not allowed to retest;
--- The reverse bending test of the steel bar with the grade E is required as a routine inspection item;
--- Increased the provisions of the steel fatigue test method;
--- Increased the rules for metallographic inspection;
--- Increased macroscopic metallographic, cross-section Vickers hardness, microstructure and test methods;
---Measurement method for increasing the gap at the end of the transverse rib;
--- Change the surface mark to "registered factory name (or trademark)" to "production of reinforced concrete for hot rolled steel products
License number (last 3 digits), deletes the steel bar with a nominal diameter of not more than 10mm, can not roll the mark, can use the hanging sign
Methods";
--- Removed Appendix A, "Methods for Measuring the Total Elongation of Rebar under Maximum Force".
This section uses the redrafting method to refer to ISO 6935-2.2015 "Steel for reinforced concrete Part 2. Ribbed steel bars", and
The degree of conformity of ISO 6935-2.2015 is non-equivalent.
This part was proposed by the China Iron and Steel Association.
This part is under the jurisdiction of the National Steel Standardization Technical Committee (SAC/TC183).
This section is mainly drafted by. China Metallurgical Construction Research Institute Co., Ltd., Metallurgical Industry Information Standards Institute, Shougang Changzhi Steel Co., Ltd.
Company, Shandong Iron and Steel Co., Ltd. Laiwu Branch, Jiangsu Shagang Group Co., Ltd., Wuhan Iron and Steel Group Kunming Iron and Steel Co., Ltd., Fu
Jianshang Sangang (Group) Co., Ltd., Jinan Iron and Steel Group Co., Ltd., Jiangsu Yonggang Group Co., Ltd., Hebei Jinxi Iron and Steel Group Co., Ltd.
Company, Hebei Jingye Iron and Steel Co., Ltd., Zhongtian Iron and Steel Group Co., Ltd., Jiangsu Shente Iron and Steel Co., Ltd., Fushun New Steel Co., Ltd.
Company, Tangshan Donghua Iron and Steel Enterprise Group Co., Ltd., Jiangsu Xinxin Iron and Steel Group Co., Ltd., Iron and Steel Research Institute.
Participated in the drafting of this section. Xuanhua Iron and Steel Group Co., Ltd., Shiheng Special Steel Group Co., Ltd., Jiangyin Xicheng Iron and Steel Co., Ltd.
Company, Guangzhou Yufeng Enterprise Group Co., Ltd., Guangdong Yougang Iron and Steel Co., Ltd., Sichuan Dazhou Iron and Steel Group Co., Ltd., Guangxi
Shenglong Metallurgical Co., Ltd., Yancheng Lianxin Iron and Steel Co., Ltd.
Drafters of this section. Zhu Jianguo, Wang Limin, Chen Jie, Feng Chao, Yang Caifu, Zhou Yuli, Wang Middle School, Li Xiaobo, Su Hezhou, Luo Zhiwen,
Qi Caixia, Chen Huabin, Zhao Yichen, Ma Linjun, Dong Caiping, Wang Yue, Deng Qizhi, Jiang Jun, Lin Guangxiong, Xu Bingwei, Sun Qingliang, Nie Wenjin, Zhao Yu,
Liu Jianfeng, Li Chengjun, Wu Huiying, Zhang Yuhai, Zhang Jueling, Zhou Xiaoqin, Liang Baocai, Wang Bingjie, Wu Jianzhong, Liu Gee, Yu Zhiliang, Wang Yuxi,
Wu Yunpeng, Wang Hongbin, Wang Changsheng, Pan Shiqun, Wen Ji, Zhou Shiwen, Ke Xueli, Chen Chunrong, Jiang Shanming, Shen Junjie, Xiao Lijun, Zhang Guangyong,
Li Yuanting, Cai Hengzhong, Li Jing, Wang Changcheng.
---GB 1499-1979, GB 1499-1984, GB 1499-1991, GB 1499-1998;
---GB/T 1499.2-2007.
This part of GB/T 1499 specifies the terms and definitions, classifications, and cards for hot-rolled ribbed steel bars (hereinafter referred to as steel bars) for reinforced concrete.
No., order content, size, shape, weight and tolerance, technical requirements, test methods, inspection rules, packaging, signs and quality certificates.
This section applies to ordinary hot-rolled ribbed steel bars and fine-grained hot-rolled ribbed steel bars for reinforced concrete.
This section does not apply to regenerated steel bars and residual heat-treated steel bars that are re-rolled from finished steel.
Permissible deviation of chemical composition of finished products of GB/T 222 steel
GB/T 223.5 Determination of acid-dissolved silicon and total silicon content - Reducing silyl molybdate spectrophotometric method
GB/T 223.11 Determination of chromium content in steels and alloys - either titration or potentiometric titration
GB/T 223.12 Methods for chemical analysis of steels and alloys - Sodium carbonate separation - Diphenylcarbonyl hydrazide photometric method
GB/T 223.14 Methods for chemical analysis of steels and alloys - Determination of vanadium content by extraction spectrophotometric method
GB/T 223.19 Methods for chemical analysis of steels and alloys - s.
GB/T 223.23 Determination of nickel content in steels and alloys - succinimide spectrophotometric method
GB/T 223.26 Determination of molybdenum content of steels and alloys - thiocyanate spectrophotometric method
GB/T 223.37 Methods for chemical analysis of steels and alloys - Distillation separation - Determination of nitrogen content
GB/T 223.40 Determination of bismuth content of steels and alloys
GB/T 223.59 Determination of phosphorus content in steels and alloys - phosphine molybdenum blue spectrophotometric method and bismuth phosphomolybdate blue spectrophotometric method
GB/T 223.63 Determination of manganese content by sodium periodate (potassium) photometric method
GB/T 223.85 Determination of sulfur content of steel and alloys - Infrared absorption method after induction furnace combustion
GB/T 223.86 Determination of total carbon content of steels and alloys - Infrared absorption method after induction furnace combustion
General provisions for GB/T 2101 steel acceptance, packaging, marking and quality certificates
GB/T 4336 Determination of multi-element content of carbon steel and medium-low alloy steels by spark discharge atomic emission spectrometry (conventional method)
GB/T 4340.1 Vickers hardness test for metallic materials - Part 1. Test methods
GB/T 6394 Determination of average grain size of metals
GB/T 13298 metal microstructure inspection method
GB/T 20066 Sampling and sample preparation method for samples for determination of chemical composition of steel and iron
GB/T 20123 Determination of total carbon and sulfur content of steels - Infrared absorption method after high-frequency induction furnace combustion (conventional method)
GB/T 20124 Determination of nitrogen content of steels - Insulating gas fusion heat conduction method (conventional method)
GB/T 20125 Determination of multi-element content of low alloy steels by inductively coupled plasma atomic emission spectrometry
GB/T 28900 steel test method for reinforced concrete
Numerical correction of YB/T 081 metallurgical technical standard and determination of test value
JGJ18 steel bar welding and acceptance procedures
JGJ107 Technical Specification for Mechanical Connection of Rebar
Ordinary hot rolled steel bars hotroledbars
Steel bars delivered in hot rolled condition.
Fine grain hot rolled steel bars hotroledbarsoffinegrains
In the hot rolling process, fine grain steel bars formed by controlled rolling and controlled cooling processes have a grain size of 9 or less.
Ribbed steel ribbedbars
The cross-section is usually circular and the ribbed concrete structure is made of steel.
Longitudinalrib
Uniform continuous rib parallel to the axis of the reinforcing bar.
Cross rib transverserib
Other ribs that are not parallel to the axis of the reinforcing bar.
Crescent rib reinforcements crescentribbedbars
The longitudinal section of the transverse rib is crescent-shaped and does not intersect the longitudinal ribs.
Nominal diameter nominaldiameter
The diameter of a circle equal to the nominal cross-sectional area of the steel bar.
Relative rib area specificprojectedribarea
The ratio of the projected area of the transverse rib on the plane perpendicular to the axis of the reinforcing bar to the product of the nominal circumference of the reinforcing bar and the spacing of the transverse ribs.
Rib height ribheight
The distance from the highest point of the rib to the surface of the core perpendicular to the axis of the rebar is measured.
Rib spacing ribspacing
The distance between the centers of two adjacent transverse ribs measured by the parallel bar axis.
In an infinite number of tests, the quantile value corresponding to a specified probability.
Base circle core
The cross section of the steel bar does not include the cross section of the transverse ribs and the longitudinal ribs.
4 classification, grade
4.1 Steel bars are classified into 400, 500, and 600 grades according to the yield strength characteristic values.
4.2 The composition of the steel grade and its meaning are shown in Table 1.
Category brand number constitutes the meaning of English letters
Yield strength characteristics by HRB
Value E constitutes
HRB---hot rolled ribbed steel (Hotroled)
RibbedBars) abbreviation.
E---"Earthquake" first letter of "Earthquake"
Yield strength by HRBF
Value E composition
HRBF---added after the English abbreviation of hot-rolled ribbed steel bar
"fine" English (Fine) first letter.
5 Ordering content
The contract ordered in accordance with this section shall include at least the following contents.
a) the number of this part;
d) nominal diameter, length and weight (or quantity, or weight) of the reinforcement;
e) Special requirements.
6 Dimensions, shape, weight and tolerance
6.1 Nominal diameter range
The nominal diameter of the steel bars ranges from 6mm to 50mm.
6.2 Nominal cross-sectional area and theoretical weight
The nominal cross-sectional area of the steel bars and the theoretical weight are listed in Table 2.
Theoretical weight a
a Theoretical weight is calculated as a density of 7.85 g/cm3.
6.3 Allowable deviation of surface shape and size of steel bars
6.3.1 The design principle of transverse ribs of steel bars shall comply with the following requirements.
a) The angle β between the transverse rib and the axis of the steel bar should be not less than 45°. When the angle β is not more than 70°, the direction of the transverse ribs of the steel bars on opposite sides
b) The nominal spacing of the transverse ribs shall not be greater than 0.7 times the nominal diameter of the steel bars.
c) The angle α between the side of the transverse rib and the surface of the steel bar shall not be less than 45°.
d) The sum of the gaps between the ends of the transverse ribs on the adjacent sides of the steel bar (including the longitudinal rib width) shall not exceed 20% of the nominal circumference of the steel bar.
e) When the nominal diameter of the steel bar is not more than 12mm, the relative rib area is not less than 0.055; the nominal diameter is 14mm and 16mm
When the relative rib area is not less than 0.060; when the nominal diameter is larger than 16 mm, the relative rib area is not less than 0.065. Relative rib area
Refer to Appendix A for the calculation.
6.3.2 Steel bars usually have longitudinal ribs or longitudinal ribs. Crescent rib steel bar with longitudinal ribs, its shape is shown in Figure 1, size and allowable partial
The difference should meet the requirements of Table 3.
6.3.3 When the deviation between the actual weight of the steel bar and the theoretical weight meets the requirements of Table 4, the deviation of the inner diameter of the steel bar is not subject to delivery.
6.3.4 The inner diameter of the crescent rib without vertical ribs may be adjusted according to the provisions of Table 3, but the weight tolerance shall still comply with Table 4.
Inner diameter d1 transverse rib height h
Longitudinal rib height h1
Cross rib width
Longitudinal rib width
Maximum clearance at the end of the transverse rib
(10% chord length of the nominal perimeter)
36 35.0
0.8 0.4 1.0 4.0
1.1 0.5 1.5 5.5
1.3 0.6 1.5 7.0
1.6 0.7 1.5 8.0
1.8 0.8 1.8 9.0
1.9 0.9 1.8 10.0
2.0 1.0 2.0 10.0
2.1 1.2 2.0 10.0
2.4 1.3 2.5 10.5
2.6 1.5 2.5 12.5
2.7 1.7 3.0 12.5
3.0 1.9 3.0 14.0
3.2 2.1 3.5 15.0
3.5 2.2 3.5 15.0
3.8 2.5 4.0 16.0
Note 1. The longitudinal rib angle θ is 0°~30°.
Note 2. Sizes a and b are reference data.
D1---the inner diameter of the steel bar;
-- --- transverse rib angle;
h --- transverse rib height;
β --- the angle between the transverse rib and the axis;
H1---vertical rib height;
θ --- longitudinal rib angle;
a --- vertical rib top width;
l --- transverse rib spacing;
b --- transverse rib top width;
Fi --- the end of the transverse rib gap.
Figure 1 Surface and cross-sectional shape of ribbed steel bars (with longitudinal ribs)
6.4 Length and tolerance
6.4.1 Length
6.4.1.1 Steel bars are usually delivered in fixed lengths, and the specific delivery length shall be indicated in the contract.
6.4.1.2 Steel bars can be delivered in coils, each plate should be a steel bar, allowing 5% of the number of disks per batch (two disks less than two plates)
Reinforcement composition. The weight of the disc is determined by negotiation between the supplier and the buyer.
6.4.2 Length tolerance
The allowable deviation of the length of the steel bar when delivered in a fixed length is 50 mm.
6.5 Bend and end
The bending of the straight bar should not affect the normal use, the bending degree per meter is not more than 4mm, and the total bending is not greater than the total length of the bar.
The end of the steel bar should be cut straight and the local deformation should not affect the use.
6.6 Weight and tolerance
6.6.1 Steel bars can be delivered according to the theoretical weight or delivered according to the actual weight. When delivered on theoretical weight, the theoretical weight is the length of the rebar multiplied by
The theoretical weight per metre of the steel bars in Table 2.
6.6.2 The allowable deviation of the actual weight of the steel bar from the theoretical weight shall be in accordance with Table 4.
Deviation between actual weight and theoretical weight
6~12 ±6.0
14~20 ±5.0
22~50 ±4.0
7.1 Smelting method
Steel should be smelted in a converter or electric arc furnace, and if necessary, it can be refined outside the furnace.
7.2 Grades and chemical composition
7.2.1 The steel grade and chemical composition and carbon equivalent (melting analysis) shall comply with the requirements of Table 5. According to the need, V, Nb,
Ti and other elements.
Chemical composition (mass fraction)
C Si Mn PS
0.80 1.60 0.045 0.045
7.2.2 Carbon equivalent Ceq (%) can be calculated according to formula (1).
Ceq=C Mn/6 (Cr V Mo)/5 (Cu Ni)/15 (1)
7.2.3 The nitrogen content of the steel should not exceed 0.012%, and the supplier can guarantee that it can be analyzed. If there is a sufficient amount of nitrogen-binding elements in the steel, including
The limitation of the amount of nitrogen can be appropriately relaxed.
7.2.4 The allowable deviation of the chemical composition of the finished steel bar shall comply with the provisions of GB/T 222, and the allowable deviation of the carbon equivalent Ceq shall be 0.03%.
7.3 Delivery type
Steel bars are usually delivered in straight bars, and bars with a diameter of no more than 16 mm can also be delivered in coils.
7.4.1 The lower yield strength of steel bars ReL, tensile strength Rm, elongation after fracture A, maximum force total elongation Agt, etc.
Meet the requirements of Table 6. The mechanical property characteristic values listed in Table 6, except R°eL/ReL can be used as the maximum guaranteed value of the delivery inspection, other mechanics
The eigenvalue can be used as the minimum guaranteed value for the delivery inspection.
Maximum force total elongation
R°m/R°eL
R°eL/ReL
16 7.5 - -
- 9.0 1.25 1.30
15 7.5 - -
HRB600 600 730 14 7.5 - -
Note. R°m is the measured tensile strength of the steel bar; R°eL is the measured yield strength of the steel bar.
7.4.2 The elongation at break of the nominal diameter of 28mm~40mm steel bars can be reduced by 1%; the nominal diameter is greater than 40mm.
The post-break elongation A of the steel bar can be reduced by 2%.
7.4.3 For steel bars without significant yield strength, the lower yield strength characteristic value ReL shall be the specified plastic elongation strength Rp0.2.
7.4.4 The elongation type can be selected from A or Agt, but Agt should be used for arbitration testing.
7.5.1 Bending performance
The steel bars should be subjected to a bending test. After bending the diameter of the bending head according to Table 7, the surface of the steel bar shall not be generated.
Table 7 is in millimeters
Brand nominal diameter d bending head diameter
6~25 4d
28~40 5d
>40~50 6d
6~25 6d
28~40 7d
>40~50 8d
7.5.2 Reverse bending performance
7.5.2.1 Reverse bending tests shall be carried out on steel bars with grade E. After the reverse bending test, the surface of the steel bar subjected to bending shall not be produced.
7.5.2.2 According to the requirements of the purchaser, other grades of steel bars may also be subjected to a reverse bending test.
7.5.2.3 The bending test may be replaced by a reverse bending test.
7.5.2.4 The bending head diameter of the reverse bending test is increased by a nominal diameter of the steel bar corresponding to the bending test.
7.6 Fatigue performance
Fatigue performance tests can be performed according to the requirements of the purchaser. The technical requirements and test methods for fatigue testing shall be in accordance with GB/T 28900
7.7.1 The welding and mechanical joining process of steel bars and the quality inspection and acceptance of joints shall comply with the relevant standards of JGJ18 and JGJ107.
7.7.2 The welding process of HRBF500 and HRBF500E steel bars shall be determined by experiment.
7.7.3 HRB600 steel bars are recommended to be connected by mechanical connection.
7.8 grain size
The actual grain size of the fine-grained hot-rolled steel bar is 9 or finer. For example, the supplier can guarantee that the grain size test can be omitted.
7.9 Metallographic organization
The metallographic structure of the steel bar should be mainly ferrite plus pearlite, and there should be no tempered martensite structure on the base circle. Macroscopic metallographic section of steel bar
Vickers hardness and microstructure should meet the requirements of Appendix B. If the supplier can guarantee that it can not be tested.
7.10 Surface quality
7.10.1 Steel bars shall be free from harmful surface defects.
7.10.2 When the weight, size, cross-sectional area and mechanical properties of the wire brushed specimen are not lower than the requirements of Chapters 6 and 7, rust
Skin, uneven surface or iron oxide scale is not a reason for rejection.
7.10.3 When a specimen with a surface defect other than the one specified in 7.10.2 does not meet the mechanical properties or process performance requirements, it is considered
These defects are harmful.
8.1 Inspection items
8.1.1 The inspection items, sampling methods and test methods for each batch of steel bars shall comply with the requirements of Table 8.
Serial number test item sampling quantity/sampling method test method
Chemical composition a
(melting analysis)
1 GB/T 20066
GB/T 223 related parts specified in Chapter 2, GB/T 4336,
GB/T 20123, GB/T 20124, GB/T 20125
2 Stretching 2 Different root (disk) steel bars cut GB/T 28900 and 8.2
3 Bending 2 different root (disk) steel bars cut GB/T 28900 and 8.2
4 Reverse bending 1 1 (disk) steel bar cutting GB/T 28900 and 8.2
5 size by root (disk) - 8.3
6 surface by root (disc) - visual
7 weight deviation 8.4
8 Metallographic organization 2 Different root (disk) steel bars cut GB/T 13298 and Appendix B
a The test method for chemical composition is preferred to use GB/T 4336. When there is any dispute over the results of chemical analysis, the arbitration test shall be as specified in Chapter 2.
The relevant part of GB/T 223 is carried out.
8.1.2 Fatigue performance, grain size and joint performance are only type tested, ie only major changes in raw materials, production processes and equipment, and new products
Inspection is carried out at the time of production. The type inspection sampling method and test method shall comply with the provisions of Table 9.
1 Fatigue performance 5 different root (disk) steel cut GB/T 28900
2 grain size a 2 different root (disk) steel cut GB/T 6394
3 connection performance JGJ18, JGJ107
a Reinforced grain grain inspection should be carried out under delivery.
8.2 Tensile, bending and reverse bending tests
8.2.1 Tensile, Bending, and Reverse Bending Test specimens are not allowed to be turned.
8.2.2 Calculate the strength of the steel bars. Use the nominal cross-sectional area listed in Table 2 for the cross-sectional area.
8.2.3 Reverse bending test, firstly bend 90° in the forward direction, and keep the sample after positive bending at a temperature of 100 °C ± 10 °C.
30 min, after natural cooling, reverse bending 20 °. Both bending angles should be measured while maintaining the load. When the supplier can guarantee the steel bar
For the reverse bending performance after aging, the sample after the forward bending can also be directly bent at room temperature.
8.3 Dimensional measurement
8.3.1 The inner diameter of the steel bar shall be measured to the nearest 0.1 mm.
8.3.2 The measurement of the height of the longitudinal ribs and transverse ribs of the steel bars shall be carried out by measuring the average value of the center heights of the transverse ribs on both sides of the same section.
For the large outer diameter, subtract the inner diameter of the area, and half of the obtained value is the height of the rib, which should be accurate to 0.1mm.
8.3.3 The transverse rib spacing of the steel bars is measured by measuring the average rib distance. That is, the first and eleventh transverse ribs on the side of the reinforcing bar are measured.
Center distance, the value divided by 10 is the transverse rib spacing, should be accurate to 0.1mm.
8.3.4 Reinforcement transverse rib end gap measurement product chord length between two ends of two adjacent transverse ribs projected perpendicular to the plane of the rebar axis, measured
The quantity diagram is shown in Figure 2.
Figure 2 Schematic diagram of the measurement of the gap at the end of the transverse rib
8.4 Measurement of weight deviation
8.4.1 When measuring the weight deviation of the steel bar, the sample shall be taken from different root steel bars, the quantity shall be not less than 5, and the length of each sample shall not be less than
500mm. The length should be measured one by one and should be accurate to 1mm. When measuring the total weight of the sample, it should be accurate to not more than 1% of the total weight.
8.4.2 The deviation between the actual weight of the steel bar and the theoretical weight is calculated according to formula (2).
Weight deviation =
Actual total weight of the sample - (total length of the sample × theoretical weight)
Total length of sample × theoretical weight ×
8.5 Macroscopic metallographic, cross-section Vickers hardness, microstructure inspection
The inspection of macroscopic metallographic, cross-section Vickers hardness and microstructure shall be carried out in accordance with the provisions of Appendix B. When there is any objection to the test results,
Microstructure is used as the basis for arbitration.
8.6 Numerical repair
The numerical repair and judgment of the test results shall comply with the provisions of YB/T 081.
9.1 Inspection classification
The inspection of steel bars is divided into eigenvalue inspection and delivery inspection.
9.2 eigenvalue test
9.2.1 The eigenvalue test applies to the following situations.
a) the supplier's inspection of product quality control;
b) The request by the acquirer shall be subject to the agreement of the agreement between the supplier and the buyer;
c) Third-party product certification and arbitration testing.
9.2.2 The eigenvalue test shall be carried out in accordance with the rules of Appendix C.
9.3 Delivery inspection
The delivery inspection is applicable to the inspection of the acceptance of the steel bar.
9.3.2 Group Approval Rules
9.3.2.1 Rebar should be inspected and accepted in batches. Each batch consists of the same grade, the same tank number, and the same size of steel. Weight per batch
Usually no more than 60t. For a portion over 60t, for each additional 40t (or less than 40t), add a tensile test specimen and a bend
9.3.2.2 Allow mixed batches of different furnace numbers from the same grade, the same smelting method, and the same casting method, but the carbon content of each furnace tank number
The difference is not more than 0.02%, and the difference in manganese content is not more than 0.15%. The weight of the mixed batch is no more than 60t.
9.3.3 Inspection items and sampling quantities
The steel bar inspection items and sampling quantities shall comply with the requirements of Table 8 and 9.3.2.1.
The inspection results of the steel bars (including the steel bars after the coils are straightened) shall comply with the relevant provisions of Chapters 6 and 7.
9.3.5 Re-inspection and judgment
The re-inspection and determination of steel bars shall comply with the provisions of GB/T 17505. The weight deviation of the steel bar is not allowed to be retested.
10 Packaging, sign and quality certificate
10.1 The surface marking of steel bars shall comply with the following requirements.
a) Rebar should be marked with the grade mark on its surface, the serial number of the manufacturer (3 digits after the license) and the nominal diameter of the millimeter.
Roll on the registered factory name or trademark.
b) Rebar grades are expressed in Arabic numerals or Arabic numerals plus English letters. HRB400, HRB500 and HRB600 respectively
4, 5, and 6 indicate that HRBF400 and HRBF500 are represented by C4 and C5, respectively, and HRB400E and HRB500E are respectively represented by 4E and 5E.
It is indicated that HRBF400E and HRBF500E are represented by C4E and C5E, respectively. The name of the factory is indicated by the Chinese pinyin prefix. Nominal diameter
The number of meters is expressed in Arabic numerals.
c) The mark shall be clear and clear. The size of the mark shall be appropriately specified by the supplier according to the diameter of the steel bar, and the transverse rib intersecting the mark may
10.2 In addition to the above provisions, the packaging, marking and quality certificates of steel bars comply with the relevant provisions of GB/T 2101.
Formula for calculating the relative rib area of steel bars
A.1 The relative rib area fr of the steel bar can be calculated according to formula (A.1).
K×FR×sinβ
π×d×l
K --- number of transverse ribs (two ribs, K = 2);
FR --- longitudinal section of a rib, in square millimeters (mm2);
β --- the angle between the transverse rib and the axis of the steel bar, in degrees (°);
d --- nominal diameter of steel bars, in millimeters (mm);
l --- transverse rib spacing in millimeters (mm).
A.2 The geometric parameters of the known steel bars, relative to the rib area fr, can also be calculated by the approximate formula (A.2).
(d×π-∑fi) ×(h 4h1/4)
6×d×π×l
∑fi --- the sum of the gaps between the ends of the transverse ribs on the adjacent two sides of the steel bar (including the width of the longitudinal ribs), in millimeters (mm);
h --- The height of the midpoint of the transverse rib, in millimeters (mm);
H1/4 --- The height of the transverse rib is one quarter higher, in millimeters (mm);
Macroscopic metallographic phase, cross-section Vickers hardness, microstructure and test method
B.1 Macro Metallography
B.1.1 Cut the steel bar into a cylindrical sample with a sawing machine. The sample shall not be affected by high temperature.
B.1.2 The section of the specimen shall be ground and polished.
B.1.3 Etching with 2%~5% nitric acid-alcohol solution, the etching time should be 5s~10s.
B.1.4 If the section of the specimen has a macroscopic metallographic feature with uniform contrast as shown in Fig. B.1a), it can be directly judged as qualified.
B.1.5 If the macroscopic metallographic phase of the sample has a closed loop around the base circle of the section which is significantly different from the internal zone contrast, as shown in Figure B.1b),
It is designated as non-hot rolled steel.
B.1.6 If the macroscopic metallographic phase of the sample appears to have a non-closed ring that is significantly different from the internal zone contrast, as shown in Figure B.1c),
The test is carried out by the method of the Vickers hardness specified in B.2 or the microstructure specified in B.3.
Figure B.1 Typical macroscopic metallographic characteristics of steel bars
B.2 Section Vickers hardness
B.2.1 The Vickers hardness test of the section can be carried out on the specimen of the macroscopic m......
Related standard: GB/T 1499.1-2017 GB/T 2101-2017