ICS 77.140.60 H 44
YB
Ferrous MetallurgyProfessionalStandard ofthe People's Republic of Chine
YB/T42642020 ReplaceYB/T4264—2011
Steel wire rod for bridge cable wire
桥梁缆索钢丝用盘条
（Eng/ishTrans/ation）
Implementation date: 202X-0X-XX
Issue date: 202X-0X-XX
IssuedbyNational ministry of industry and informationofthe
People'sRepublicof China YB/T4264—2020
Foreword
SAc/Tc 183 is in charge of this English translation. In case of any doubt about the contents of English translation, the Chinese original shall be considered authoritative. This standard is drafted in accordance with the rules given in the GB/T 1.1—2009(Directives for standardization-Part 1:Rules for the structure and drafting of standards). This standard will replace YB/T 4264—2011: Hot-rolled wire rod for bridge cable wire,the main technical changes are as follows: Revised the title of standard ;
Added designation of steel grades; Revised the permissible tolerances in diameter and out-of roundness of wire rod; Revised the name of steel grades; Deleted QS77Mn and added QS97; Revised requirements of partial chemical composition; Revised requirements of delivery condition; -Revised requirements of mechanical property; -Revised requirements of non-metallic inclusions; Revised microstructure requirement; Revised batch rule. The standard was proposed by China Iron and Steel Association. This standard dwaspreparedbySAC/TC183 (Technical Committee 183onSteelof Standardization Committee of China) The previous edition of this standard is as follows:
YB/T4264-2011
2 YB/T42642020
Steel wire rod for bridge cable wire
1 Scope
This standard specifies the designation, ordering information, dimension, shape, mass and permissibletolerances,technical requirements,testmethods,inspection rule,packaging, marking and quality certificate of steel wire rod for bridge cable wire.
This standard is applicable to steel wire rod for bridge cable wire
2Normativereferences
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/T222 Permissib/e to/erances for chemica/composition of stee/products GB/T223.5Stee/and iron-Determinationofacid-so/ub/esi/iconandtota/si/icon content -Reduced mo/ybdosi/icate spectrophotometric method GB/T223.11/ron,stee/anda//oy-Determinationof chromiumcontent-Visua/titration or potentiometric titration method GB/T223.18Methodsforchemica/ana/ysisofironstee/anda//oy.Thesodiumthiosu/fate separation iodimetric method for the determination of cupper content GB/T223.19Methodsforchemicalanalysisofiron,stee/anda/loy--The neocuproine-ch/oroform extraction photometric method for the determination of copper content content GB/T223.37Methodsfor chemica/ana/ysisof iron,stee/and a//oy--Theindopheno/b/ue photometric methods for the determination of nitrogen content after disti//ation separation GB/T223.53 Methods for chemica/ana/ysis of iron,stee/anda//oy--The f/ame atomic absorption spectrophotometric method for the determinationof copper content GB/T223.59 /ron,stee/anda/loy.Determinationofphosphoruscontent.Bismuth phosphomo/ybdate b/ue spectrophotometic method and antimony phosphomo/ybdate b/ue spectruophotometricmethod GB/T223.60 Methods for chemica/ana/ysis of iron,stee/anda//oy--The perch/oric acid dehydration gravimetric method for the determination of si/icon content GB/T223.63Methodsforchemica/analysisofiron,stee/anda/loy--The sodium(potassium)periodatephotometricmethod forthedeterminationof manganesecontent GB/T 223.64/ron,stee/ and al//oy.Determination of manganese content.F/ame atomic absorption spectrometric method
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GB/T223.85Stee/andiron.Determinationofsu/furcontent./nfraredabsorptionmethoa after combustion in an induction furnace GB/T 223.86 Stee/ and iron.Determination of tota/ carbon content./nfrared absorption method after combustion in an induction furnace GB/T224Determinationof thedepthof decarburization ofstee/s Gb/T228.1Metal/licmateria/s-Tensi/etesting-Part1:Method of testatroomtemperature GB/T 2101 Genera/ requirement of acceptance,packaging,marking and certification for section stee/ GB/T2975Stee/andstee/products.Locationandpreparationof samp/esandtestpieces formechanica/testing(eqv，/S0377:1997) GB/T 4336 Carbon and /ow-a//oy stee/.Determination of mu/ti-e/ement contents.Spark discharge atomic emission spectrometric method (routine method) GB/T6394 Determination of estimatingtheaveragegrain size of metal GB/T10561-2005 Stee/.Determination of content of nonmeta//icinc/usions.Micrographic method using standards diagrams GB/T13298Inspection methodsofmicrostructure for meta/s GB/T20066 Stee/and iron.Samp/ing andpreparationof samp/esforthedetermination of chemica/composition GB/T20123 Stee/ and iron-Determination of tota/ carbon and su/fur content /nfrared absorptionmethodaftercombustioninaninductionfurnace(routinemethod) GB/T20124 Stee/ and iron -Determination of nitrogen content -Therma/ conductimetric method after fusion in a current of inert gas (Routine method) YB/T169Meta//ographic testmethodof sorbiteinhigh carbonstee/wirerod YB/T 4412Determination of grain boundary cementite in high carbon stee/ wire rod
3 Designation
InthedesignationQS##，"Q"meansbridge;“s"meansbridgecable;##istheindicative average content (per ten thousand) of carbon. For example:Qs82 Q——bridge S——bridge cable 82- -averagecontent of carbonis 82perten thousand
4OrderingInformation
Contracts or orders for wire rod under this standard shall include the following information:
a)Standard number. b) Product name; c) Steel grade; d) Dimension; e) Mass(quantity); f) Delivery condition;
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g) Mechanical property classification; h) Decarburization classification; i) Special requirements.
Dimensions, Shape,Mass andPermissibleTolerances
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5. 1 The permissible tolerances in diameter and out-of roundness of wire rod shall be in accordance with Table 1. If there are any special requirements, it should be noted in the contract.
Table 1 Permissible tolerances in diameter and out-of roundness of wire rod
Nominal diameter /mm
Permissible tolerances /mm
Out-of roundness /mm
11.0~15.0
± 0. 25
≤0.32
5.2E Each coil shall be one continuous length of wire rod.The minimum weight of each coil shall be 1oookg. Special requirements shall be noted in the contract.
Technical requirements
6.1 Steel grade and chemical composition 6. 1. 1 The steel grade and chemical composition (heat analysis) shall comply with Table 2.
Table2 Steelgradeand chemicalcomposition
Chemical composition(mass fraction)/%
steel grade
Si
Mn
Cr ≤0.35 ≤0.35
Cu ≤0.20 ≤0.20 ≤0.20 ≤0.20
c
P
s
QS82 0.80~0.85 0.12~1.00 0.30~0.90 ≤0.020 ≤0.010 QS87 0.85~0.90 0.12~1.00 0.30~0.90 ≤0.020
≤0.010
QS92 0.90~0.95 0.12~1.20 0.30~0.90 ≤0.020 ≤0.010 ≤0.35 QS97 0.95~1.00 0.12~1.20 0.30~0.90 ≤0.020
≤0.010
≤0.35
6. 1. 2 The addition of trace alloy elements shall be determined by the agreement between supplier and purchaser. 6. 1.3 3Nitrogen content of steels shall not exceed 0.oo7%.Nitrogen content may notbe analyzed when its conformity is guaranteed by the supplier. 6.1.4 The permissible deviation in chemical composition of finished products shall be inaccordancewithGB/T222. 6.1.5 5Other steel grades of wirerod shall be supplied upon mutual agreement. 6. 2 Melting method
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The steel shall be made by BOF (or EAF) and external refining.The method shall be determined by supplier if it is not required by the purchaser. 6. 3 Delivery condition The wire rod shall be supplied in hot-rolled or heat-treated condition. 6.4 Mechanical Properties 6. 4.1 The mechanical properties of the wire rod after aging shall be in accordance with Table 3.
Table 3Mechanical Properties
Tensile strength R/MPa
Reduction of area Z/%
Steel grade
Nominal diameter Nominal diameter
- ≥40 ≥36 ≥32 ≥28
II ≥30 ≥25 ≥20
II ≥32 ≥30 ≥28 ≥25
≤12.5mm ≥1230 ≥1280 ≥1330 ≥1380
>12.5mm ≥1200 ≥1250 ≥1300 ≥1350
QS82 QS87 QS92 QS97
6.4.2 The variation range of tensile strength for the same batch of wire rod shall not be greater than 80MPa. 6. 5 Decarburization The decarburization depth of wire rod shall be inspected. The depth of total decarburization (ferrite and transition layer) on each side shall be in accordance with requirement in Table 4.
Table 4 Total decarburization depth
Total decarburization depth /mm
I II II
≤0.07 ≤0.10 ≤0.12
6. 6 Non-metallic inclusions 6. 6. 1 The wire rod shall be inspected for non-metallic inclusion in accordance with Method A, GB/T10561-2005. The qualification level shall meet the requirements of Table 5
Table5Qualification level for non-metallic inclusion
Type A Thin Thick Thin Thick Thin Thick Thin Thick ≤2.0 ≤1. 0 ≤2.0 ≤1. 0 ≤1.0 ≤0.5 ≤1.5 ≤1. 0 ≤1.5
Type B
Type C
Type D
Type Qualification
DS
Level
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6.6.2 Non-metallic inclusions may also be inspected by other methods according to the requirements of the purchaser. The qual ification level shall be determined by the agreement between supplier and purchaser. 6.7 Microstructure 6.7.1The sorbite content of wire rod shalI be inspected in accordance with YB/T 169.The sorbite content shall be equal to or greater than 85%. 6.7.2 The network cementite of wire rod shall be inspected and evaluated in accordance with YB/T 4412.Its qualification level shall not exceed level 3. The network cementite may not be inspected when its conformity is guaranteed by the supplier. 6.8 Grain size The grain size of wire rod shall not be greater than grade 6. The grain size may not be inspected when its conformity is guaranteed by the supplier. 6.9Surface quality 6.9.1 The wire rod shall be free of surface defects such as cracks,folds,incrustations. or ears which may be detrimental to its use.Indentation and Iocal bumps,pits,scratches pockmarks are allowed, but the depth or height (calculated from actual dimension) must not exceed 0.10mm. 6.9.2 Head and tail of wire rod with harmful defects shall be cut. The cross section of wire rod shall be free of shrink holes, layers or inclusions. 6.9.3The scale weight on wire rod surface shall not be greater than 7kg/t. The scale weight may not be inspected when its conformity is guaranteed by the supplier 6.10 Special requirements According to the purchaser' s requirement, the inspection of other items may be carried out upon agreement between the supplier and purchaser.
7 Test methods
7. 1 The test items, sample quantity, sampling method and location of each batch of wire rods shall be in accordance with Table 6.
Table 6 Test items, sample quantity, sampling method and location of wire rods
sample sampling method quantity and location
NO.
Test items Chemical
Test methods
1/heat
GB/T 20066 GB/T223 series、GB/T 4336、GB/T20123
composition (heat
1
analysis) Tensile test Decarburization
GB/T 2975
GB/T 228.1 GB/T 224
2/batch 2/batch from two coils
2 3
7 YB/T42642020
2/batch from two coils 2/batch from two coils 2/batch from two coils
GB/T 6394 YB/T 169 GB/T 13298 GB/T 105612005 YB/T 4412
4 5 6 7 Non-metallic inclusion 2/batch from two coils
Grain size Sorbite content Microstructure
2/batch
8 Network cementite 9
from two coils Head and tail shall be removed
Each coil Each coil several from each coil
Caliper, micrometer,
Dimension
10 Surface quality
Visual inspection
一
1 coil or several coils/batch
11
Scale
Clause 7.2 of this standard
7. 2 Scale inspection method
Take one or several coils of wire rod as samples and weigh them. Weigh the samples again after removing the surface scales. The weight difference between these two values is the scales weight of the samples. The scales weight of wire rod per ton is calculated by the following formula:
Scales weight on samples (kg) Total samples weight(kg)
X1000 (kg/t)
8 Inspection rule
8.1 Inspection and acceptance Delivery inspection and acceptance of wire rod shall be carried out by the quality supervision department of the manufacturer. The purchaser reserves the right to carry out any inspection and acceptance for any test item specified in this standard. 8.2 Batch rule Wire rods shal be inspected in batch. Each batch consists of wire rod with the same grade, the same heat number, the same dimension and the same heat treatment (or hot rolling) 8.3 Retest and judging rule if one item does not conform to the corresponding provisions of this standard, ,the unqualified coil shali be removed. Double sampling and reexamination from the same batch shall be done. If they are still unqualified, they should be deemed as unqualified product. The remaining coils from the same batch shall be checked one by one and the qualified ones can be delivered. 8.4 Rounding off of numerical values All inspection result of steel wire rod shall be rounded off for all values, and the rounding off method shall comply with YB/T 081.
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