TB/T 2344-2012 English PDF (TB/T2344-2012)

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TB/T 2344-2012: [Including 2017XG1] Technical specifications for the procurement of 43 kg/m~75 kg/m rails
TB/T 2344-2012
RAILWAY INDUSTRY STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
ICS 45.080
S 11
Replacing TB/T 2344-2003, partial replacing TB/T 2635-2004
Technical Specifications for the
Procurement of 43kg/m ~ 75kg/m Rails
[Including Amendment No.1 [2017XG1]]
ISSUED ON: MARCH 01, 2012
IMPLEMENTED ON: JULY 01, 2012
Issued by: Ministry of Railways of PRC
Table of Contents
Foreword ... 5
1 Scope ... 7
2 Normative References ... 7
3 Terms and Definitions ... 9
4 Ordering Required Information ... 9
5 Type Size, Length, Weight and Limit Deviation ... 10
5.1 Type size and limit deviation ... 10
5.2 Straightness and distortion ... 10
5.3 Bolt hole ... 11
5.4 Rail end chamfering ... 11
5.5 Length and weight ... 13
6 Technical Requirements ... 14
6.1 Manufacturing method ... 14
6.2 Designation and chemical composition ... 14
6.3 Tensile properties ... 16
6.4 Hardness ... 16
6.5 Microstructure ... 17
6.6 Decarburization layer ... 17
6.7 Non-metallic inclusions ... 18
6.8 Macrostructure ... 19
6.9 Drop-Weight ... 19
6.10 Surface quality ... 19
6.11 Ultrasonic flaw detection ... 20
6.12 Residual stress on rail base ... 21
6.13 Fracture toughness ... 21
6.14 Fatigue crack growth rate ... 21
6.15 Fatigue ... 21
6.16 Heat treatment on the rail end ... 21
7 Test Methods ... 21
7.1 Inspection items, inspection frequency, sampling positions and test methods
... 21
7.2 Hydrogen content ... 24
7.3 Total oxygen content and nitrogen content ... 24
7.4 Hardness ... 25
7.5 Microstructure ... 25
7.6 Drop-weight ... 25
7.7 Ultrasonic flaw detection ... 26
7.8 Residual stress on the rail base ... 29
7.9 Fracture toughness ... 29
7.10 Fatigue crack growth rate ... 29
7.11 Fatigue ... 30
8 Inspection Rules ... 32
8.1 Supervision ... 32
8.2 Type inspection ... 32
8.3 Exit-factory inspection ... 32
8.4 Reinspection and judgment ... 33
8.5 Numerical rounding off ... 34
9 Marking, Quality Certificate ... 35
9.1 Marking ... 35
9.2 Quality certificate ... 36
10 Quality Assurance ... 36
10.1 Quality assurance system ... 36
10.2 Quality assurance period ... 36
Appendix A (Normative) 43kg/m ~ 75kg/m Rail Type and Size ... 38
Appendix B (Normative) Schematic Diagram of Rail Geometry Inspection
Template ... 45
Appendix C (Normative) Impermissible Defects on Rail Lateral Acid Leaching
Test Strips ... 54
Appendix D (Normative) Rail Plane Strain Fracture Toughness KIC Test Method
... 61
Appendix E (Normative) Heat Treatment Technical Condition on the End of Rail
... 65
Appendix F (Normative) Method for Measuring Longitudinal Residual Stress of
Rail Base Surface ... 68
Bibliography ... 70
Amendment No.1 [2017XG1] TB/T 2344-2012 Technical Specification for the
Procurement of 43kg/m ~ 75kg/m Rails ... 71
Technical Specifications for the
Procurement of 43kg/m ~ 75kg/m Rails
1 Scope
This Standard specifies the terms and definitions, ordering required information, type
size and limit deviation, technical requirements, test methods, inspection rules,
marking and quality certificate, quality assurance, and the like contents of 43kg/m ~
75kg/m rails.
This Standard is applicable to the 43kg/m ~ 75kg/m hot-rolled and online heat-treated
rails for the railway with the maximum running speed of 160km/h. this Standard can be
referred by the heat-treated rails for high-speed railways.
2 Normative References
The following documents are essential to the application of this document. For the
dated documents, only the versions with the dates indicated are applicable to this
document; for the undated documents, only the latest version (including all the
amendments) are applicable to this document.
GB/T 223.14 Methods for Chemical Analysis of Iron, Steel and Alloy - The N-
Benzoy-N-Phenylhydroxylamine Extraction Photometric Method for the
Determination of Vanadium Content
GB/T 223.49 Methods for Chemical Analysis of Iron, Steel and Alloy - Extraction
Separation-Chlorophosphonazo mA Spectrophotometric Method for the
Determination of the Total Rare Earth Content
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 223.62 Methods for Chemical Analysis of Iron, Steel and Alloy - The Butyl
Acetate Extraction Photometric Method for the Determination of Phosphorus
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 223.71 Methods for Chemical Analysis of Iron, Steel and Alloy - The
Gravimetric Method after Combustion in the Pipe Furnace for the Determination
of Carbon Content
GB/T 223.82 Steel and Iron - Determination of Hydrogen Content - Inert Gas
Impulse Fusion Heat Conductivity Method
GB/T 226 Test Method for Macrostructure and Defect of Steel By Etching
GB/T 228.1 Metallic Materials - Tensile Testing - Part 1: Method of Test at Room
Temperature
GB/T 230.1 Metallic Materials - Rockwell Hardness Test - Part 1: Test Method
GB/T 231.1 Metallic Materials - Brinell Hardness Test - Part 1: Test Method
GB/T 3075 Metallic Materials - Fatigue Testing - Axial-Force-Controlled Method
GB/T 4161 Metallic Materials - Determination of Plane-Strain Fracture Toughness
– KIC test
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission
Spectrometric Analysis of Carbon and Low-Alloy Steel (Routine Method)
GB/T 4340.1 Metallic Materials - Vickers Hardness Test - Part 1: Test Method
GB/T 6398 Metallic Materials - Fatigue Testing - Fatigue Crack Growth Method
GB/T 10561-2005 Steel - Determination of Content of Nonmetallic Inclusions -
Micrographic Method Using Standards Diagrams
GB/T 11261 Steel and Iron – Determination of Oxygen Content - The Pulse
Heating Inert Gas Fusion-Infra-Red Absorption Method
GB/T 13298 Metal - Inspection Method of Microstructure
GB/T 19001 Quality Management Systems - Requirements
GB/T 20066 Steel and Iron-Sampling and Preparation of Samples for the
Determination of Chemical Composition
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 20124 Steel and Iron - Determination of Nitrogen Content - Thermal
Conductimetric Method after Fusion in a Current of Inert Gas (Routine Method)
YB/T 081 Rule for Rounding off of Numerical Values and Judgement of Testing
Values for Technical Standards of Metallurgy
YB/T 951 Method of the Ultrasonic Inspection for Rails
3 Terms and Definitions
For the purpose of this document, the following terms and definitions apply.
3.1 Heat
All casting billets from the molten steel in one furnace; but excluding the first casting
billet cast into the tundish from the molten steel in the next furnace.
3.2 Sequence
The molten steel with the same designation and different heats is continuously cast in
the tundish.
3.3 Transition area
The part cast by mixing of the molten steels in the two furnaces.
3.4 On line heat-treatment
The heat-treatment that uses the residual heat of rolling to accelerate the cooling, and
obtains fine-grained pearlite structure.
4 Ordering Required Information
The user shall provide the following basic information when ordering products:
a) Product name;
b) Product standard number;
c) Rail type;
d) Steel designation and delivery status;
c) 75m rail: 71m, 72m, 73m, 74m;
d) 100m rail: 95m, 96m, 97m and 99m.
5.5.4 The length of curved and shortened rail for the rail with specified length of 75m
and 100m, as well as the length of rail with other specified length and of the shorter
rail shall be negotiated by the supplier and the purchaser, and indicated in the contract.
5.5.5 The matching quantity of the shorter rail shall be negotiated by the supplier and
the purchaser, and indicated in the contract; but shall not exceed 10% total ordering
weight of one batch; the rail with bolt hole shall not have shorter rail.
5.5.6 The rail shall be delivered by theoretical mass. Steel density is 7.85 g/cm3. The
theoretical mass of the rail can refer to Appendix A.
6 Technical Requirements
6.1 Manufacturing method
6.1.1 Rail steel shall be smelted in an alkaline oxygen converter or electric arc furnace;
and subjected to refining and vacuum degassing outside the furnace.
6.1.2 Rail shall be manufactured by the continuous casting billets.
6.1.3 Rail shall be multi-stage high pressure jet descaling during the rolling process to
effectively remove the scale.
6.1.4 The rolling compression ratio of the rail shall be no less than 9:1.
6.1.5 The rail shall be straightened by the two-stage roller straightening machine for
the horizontal axis X-Y and the perpendicular axis X-Y direction on the section. Only
once roll-straightening is allowed. If there is end or local unevenness, the four-side
press machine can be used for supplemented straightening. The drilled rail shall be
firstly conducted supplemented straightening, then drill holes.
6.1.6 The welding rail shall not be subjected to rail end heat-treatment; while the
U71Mn hot-rolled drilled rail shall be subjected to the rail end heat-treatment; when it
requires no heat-treatment, it shall be indicated in the contract; the hot-rolled drilled
rail with other steel designations shall not be subjected to the rail end heat-treatment.
6.2 Designation and chemical composition
6.2.1 The steel designation, chemical composition and residual elements (smelting
analysis) shall conform to the provisions of Tables 3 and 4. If the supplier guarantees,
the residual element test can be neglected.
6.8 Macrostructure
The macrostructure of the cross-section acid-etched test piece of the rail shall conform
to the provisions of Appendix C.
6.9 Drop-Weight
The rail shall be subjected to the drop-weight test; the specimen shall not appear
breaks after once hammering. The deflection value shall be given in the quality
certificate for reference.
6.10 Surface quality
6.10.1 The rail surface shall be free of cracks. Rail shall not fall from the height of 1m
above.
6.10.2 The running surface of the rail (i.e. rail crown), lower surface of the rail base,
and the protruding parts (except the hot-rolled marking) that affect the installation of
the joint bar within 1m from the rail end shall be ground.
6.10.3 The maximum allowable depth of the rail wear, thermal scratches, longitudinal
lines, folds, scale indentation, rolling marks, etc. formed in the hot state shall be as
follows:
a) Rail running surface 0.5mm;
b) Other parts of the rail 0.6mm.
The number of scratches on the rail running surface, lower surface of the rail base and
longitudinal fore-plate in the rail length direction is allowed to be 2 at the maximum;
their depth shall not exceed the relevant specified value. The repeated fore-plate
scratches along the same axis can be regarded as one.
The maximum width of the fore-plate scratch is allowed to be 4mm; the ratio between
the width and depth shall be greater than or equal to 3:1.
The periodic hot-rolled marks produced by the rolls can be approved as one place and
can be ground.
6.10.4 The maximum allowable depth of the defects such as longitudinal and lateral
scratches of rail formed in the cold state shall be as follows:
a) Rail running surface and lower surface of rail base 0.4mm (no lateral scratches
on the lower surface of the rail base);
b) Other parts of the rail 0.5mm.
6.10.5 The rail surface shall be free of the damage from martensite or white phase
structure, and shall be eliminated if any.
6.10.6 Surface defect detection and grinding: The surface defect depth shall be
detected by a depth detector. When the depth can’t be measured, it shall be confirmed
by test. When grinding the surface defects, the contour of the grinding surface shall be
smooth; ensure the microstructure of the rail after grinding shall not be affected.
Maximum allowable grinding depth:
a) Rail running surface 0.5mm;
b) Other parts of the rail 0.6mm.
The geometrical deviation of the rail after grinding shall conform to the provisions of
Table 1.
In the range of 1m from the welding rail to the rail end, the rail running surface and rail
head side, except for the protruding part, shall not be ground.
If the rail section size and straightness are unqualified, except for the protruding part,
shall not be treated by grinding.
When the hot and cold damage of the rail meets the requirements of 6.10.3 and/or
6.10.4, and is harmless to the use of rail, the grinding can be neglected.
6.10.7 The burrs on the rail end face and the edge surface of the bolt hole shall be
removed.
6.10.8 The surface of the rail base shall be automatically detected along the entire
length of the rail. The used equipment shall be capable of detecting the artificial defect
with the size specified in Table 9. The size tolerance of the artificial defect shall be
±0.1mm. When detecting by the rail base automatic detection technology, the detecting
range shall be at least 60mm wider than the center of the rail base. Use the test rail
with artificial defect to calibrate once every 8h. When the automatic detection
equipment can’t work properly, the manual inspection shall be conducted.
Table 9 – Size of Artificial Defect Unit: mm
6.11 Ultrasonic flaw detection
The entire length of the rail shall be continuously tested for ultrasonic flaw detection;
the defects shall not exceed φ2.0mm artificial defect equivalent.
Defect depth Defect length Defect width
8 Inspection Rules
8.1 Supervision
The purchaser reserves the right to supervise the various processes and inspections
of th...