gb 2585 - 2007 hot-rolled steel rails for railway

8/12/2019 GB 2585 - 2007 Hot-rolled Steel Rails for Railway

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ICS 77.140.60.45

H 52

National Standards of the People's Republic of China

GB 2585 2007

Hot-rolled steel rails for railway

2007-07-12 Issue 2008-02-01 Implement

Genera l Adminis t ra t ion of Qual i ty Supervis ion , Inspect ion

and Quarant ine of the People' s Republ ic of China Issue


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Hot ro lled steel rails for railway

1 Scope

This standard specifies the terms and definitions, ordering information, dimensions, shapes, masses and

tolerance, technical requirements, testing methods, inspection rules, marking and quality certificate, qualityassurance for hot rolled steel rails for railway.

This standard apply to railway that was manufactured by continuous casting billet and speed not more than160 km/h, not apply to that full-length heat treatment.

2 Normative references

The following normative documents contain provisions which, through reference in this text, constituteprovisions of this standard. For dated references, subsequent amendments to, or revisions of, any of thesepublications do not apply. However, parties to agreements based on this standard are encouraged toinvestigate 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.

GB/T 222 Permissible tolerances for chemical composition of steel productsGB/T 223 Method for chemical analysis of iron, steel and alloyGB/T 224 Determination of depth of decarburization of steel (eqv ISO 3887)GB/T 226 Etch test for macrostructure and defect of steels eqv ISO 4969 GB/T 228 Metallic materials Tensile testing at ambient temperature (eqv ISO 6892)GB/T 230.1 Metallic Rockwell hardness test-Part 1:Test method scales A,B,C,D,E,F,G,H,K,N, T

eqv ISO 6508 GB/T 231.1 Metallic materials-Brinell hardness test-Part 1:Test method (neq ISO6506-1)GB/T 2101 General requirements of acceptance, packaging, marking and certification for section steelGB/T 3075 Method of axial force controlled fatigue testing of metals(neq ISO 1099)GB/T 4161 Standard test method for plane-strain fracture toughness of metallic materials

GB/T 4336 Standard test method for spark discharge atomic emission spectrometric analysis of carbonand low-alloy steel (Routine method)GB/T10561 Steel-Determination of content of non-metallic inclusions micrographic method using standards

diagramsGB/T 13298 Metal-Inspection method of microstructureGB/T 17505 Steel and steel products-General technical delivery requirements (eqv ISO 404)GB/T 19001 Quality management systems-Requirements eqv ISO9001\ISO9002 GB/T 20066 Steel and iron-Sampling and preparation of samples for the determination of chemical

composition ISO14284 1998 IDT YB/T 951 Method of the ultrasonic inspection for rails

3 Terms and definitions

For the purposes of this standard, the following terms and definitions apply.

3.1

heat

All billets cast by one heat of liquid steel, until one certain billet cast by next heat of liquid steel ( theextension of this billet ).

3.2

sequence

Any number of heats, of the same steel grade, which undergo continuous casting in tundishes.

3.3


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transition area

Any part of steel mixed by two heats.

4 Order infor mation

The purchaser shall provide the supplier with the following information at the time of order:

a)the number of this standard;b) the rail profiles and indicated drilled rail or welded rail;c) the steel grades;d) end quenching ;e) quantity, lengths(cut length or not);f) any other special requirements.

5 Dimension shape weight and to lerance

5.1 Dimension and tolerance

5.1.1 Rail profiles and their cross section dimensions and holes dimensions are given in annex A. Otherprofiles can be supplied when agreed by purchaser and supplier and specify in the contract.

5.1.2 The tolerances of railway dimensions shall be as given in Table 1.

Table1 Dimension shape tolerances mm

items Profile class kg/m

38 43 50 60 75Gaugefigure

number

Width of rail headWH

0.5 0.5 Figure C3

Thickness of railweb a WT

+1.0

-0.5

+1.0

-0.5Figure C6

Height of fishingHF

0.6+0.6

-0.5Figure C5

Height of rail H 0.8 0.6 Figure C8

Width of rail footWF

+1.0

-2.0

+1.0

-1.5Figure C9

Profiles

Foot toe thickness b +0.75

-0.5Figure C7


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Rail asymmetry 1.5

1.2Figure C4-1

Figure C4-2

VerticalSquareness of end

Horizontal 1.0 0.8

Verticalstraightness-up

0.8 0.5

Verticalstraightness-down

0.2 0.2

End curvature

1m from each railends

Horizontalstraightness

0.5 0.5

Figure C11

Vertical flatness 0.5mm/3m

0.4mm/1m

Body

except 1m fromeach rail ends

Horizontal flatness 0.7mm/1.5m

Whole rail twist 1/10000 of whole length

shap

e

Whole rail sweep 0.5/1000 of whole length

Inclination of fishing surfaces on the basis of14mm parallel to the inclined theoretical fishing

surfaces

+1.0

-0.5

+1.0

-0.5Figure C5

Diameter 0.8 0.8Drilling holes

Location 0.8 0.8Figure C10

a Thickness of rail web shall be measured at the point of minimum thickness.

b Assurance when pass design. In case of dispute, gauge given in figure C7 is apply.

5.2 Shape tolerances

5.2.1 The tolerances of shape shall be as given in Table 1.

5.2.2 The foot base concavity shall not exceed 0.4mm.

5.2.3 Finished roller straightened rails shall not have curve like wave or rigidity.

5.2.4 The chamfer angle of drilling hole shall be 45 and 0.8mm 2.0mm in depth.

5.3 Length and length tolerance

5.3.1 Length

5.3.1.1 The cut length of standard rail shall be 12.5m 25m 50m and 100m.

5.3.1.2 Curve shorten length of rail


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12.5m 12.46m 12.42m 12.38m.

25m 24.96m 24.92m 24.84m

5.3.1.3 Shorten length of rail

12.5m 9m 9.5m 11m 11.5m 12m

25m 21m 22m 23m 24m 24.5m

The quantities of short length rails shall be agreed by purchaser and supplier and specify in the contract. Theweight of short length rails shall not exceed 10% of ordering gross( include drilled rail and welded rail ). Tothe rail of 50 kg/m, 60 kg/m, 75 kg/m shorten length of rail shall not included.

5.3.1.4 To the curve shorten length of 50m, 100m cut length rails and short length rail, the length shall beagreed by purchaser and supplier, and the quantities of short length rails shall specified in the contract.

5.3.1.5 Rails of other length can be supplied when agreed by purchaser and supplier.

5.3.2 Length toleranceThe length tolerance of rail shall be as given in table 2.

Table 2 length tolerance Ambient temperature :20

Lengthm Tolerance mm

Drilled rail 25 6

25 10Welded rail

25 Agreed by purchaser and supplier

5.4 Weight

Rails shall be delivered in theoretical weight, the calculate data is given in annex A.

6 Technical requirements

6.1 Manufacture methods

6.1.1 Continuous casting blooms made from basic oxygen killed steel or electric arc furnace killed steel shallbe used for the manufacture of rails.

6.1.2 To descaling during the rolling a processes, the high-pressure injection method shall be used.

6.1.3 The cross-sectional area of the rail shall not exceed one ninth that of the bloom from which the rail isrolled.

6.1.4 For the avoidance of hydrogen flakes, liquid steel shall be conducted vacuum degassing or bloomsand rails shall be conducted slowly cooling.

6.1.5 Welded rails do not need heat treatment of rail ends; it is shall specified in the contract , provided thatU74, U 71Mn, U70Mn drilled rails do not need heat treatment of rail ends.

6.2 Steel grades and chemical composition


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6.2.1 Steel grades, chemical composition and residual elements heat analysis shall apply to table 3,table 4 and requirements of 6.2.1.1 and 6.2.1.2 The residual elements may not tested if the supplier canmake an assurance.

Table3 Steel grades and chemical composition

Chemical composition %Steel grades

C Si Mn S P V a Nb a RE

U74 0.68~0.79 0.13~0.28 0.70~1.00 0.030 0.030

U71Mn 0.65~0.76 0.15~0.35 1.10~1.40 0.030 0.030

U70MnSi 0.66~0.74 0.85~1.15 0.85~1.15 0.030 0.030

U71MnSiCu 0.64~0.76 0.70~1.10 0.80~1.20 0.030 0.030

0.030

U75V 0.71~0.80 0.50~0.80 0.70~1.05 0.030 0.030 0.04~0.12

0.010

U76NbRE 0.72~0.80 0.60~0.90 1.00~1.30 0.030 0.030 0.02~0.05 0.02~0.05

U70Mn 0.61~0.79 0.10~0.50 0.85~1.25 0.030 0.030 0.030

0.010

a Except V in U75V and Nb in U76NbRe are additional elements , Nb and V are residual elements in othersteel grades.

Table 4 Maximums residual elements mass, %

Cr Mo Ni Cu a Sn Sb Ti Cu+10Sn Cr+Mo+Ni+Cu

0.15 0.02 0.10 0.15 0.040 0.020 0.025 0.35 0.35

a the content of Cu in U71MnSiCu is 0.10~0.40%

6.2.1.1 The hydrogen contents of the liquid steel shall not exceed 2.5 10 -4 . If the hydrogen contents ofthe liquid steel exceed 2.5 10 -4 the blooms shall be slowly cooled. The hydrogen contents of the liquidsteel need not test when the blooms are slowly cooled. The hydrogen contents of product rails shall notexceed 2.010 -4%.

6.2.1.2 Total oxygen content of liquid steel or product rail shall not exceed 30 10 4 . Total oxygen content

need not test when the supplier can make an assurance that non-metallic inclusions in rails conform to therequirements of this standard.

6.2.2 Product analysis

If purchaser requires the product analysis, the composition tolerance which described in table 3 shall apply torequirements of GB/T222.

6.3 Delivery condition

The rail shall be supplied in hot rolled condition.

6.4 Mechanical properties

Mechanical properties of rails shall be as given in table 5.


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Table5 Mechanical properties

Mechanical propertiesSteel grade Tensile strength R m

N/mm 2 min. Elongation A% min.

U74 780 10U71Mn

U70MnSiU71MnSiCu

880 9

U75VU76NbRE

980

U70Mn 880

9

When the test pieces is taken from hot saw sample rails, the results of Acan smaller 1% (absolute value) than the given value.

6.5 Heat treatment of rail ends

The rails need to heat treatment of rail ends, quenching layer shall be like a cap and free of quenching

cracks. The requirements shall comply with requirements of annex B.

6.6 Macrostructure

6.6.1The transverse macrostructures of acid etch rail test pieces shall comply with requirements of annex F.

6.6.2 The rails shall be free of hydrogen flakes.

6.7 Microstructure

The microstructure shall be pearlite but grain boundary ferrite may occur, there shall be no martensite,bainite or grain boundary cementite.

6.8 Decarburization

The decarburization depth of rail shall below 0.5mm.

6.9 Non-metallic inclusions

Non-metallic inclusions of rails shall comply with the following requirements: group A shall not exceed level2.5, group B aluminate type , group C silicate type and group D globular oxide type shall notexceed level 2.0 respectively.

6.10 Drop weight test

Rails shall be conducted drop weight test. The specimens shall not fracture after one break. Deflection shallbe noted in the certification as reference.

6.11 Ultrasonic test

6.11.1 All rails shall be ultrasonically tested by a continuous process.

6.11.2 The minimum cross-sectional area examined by the ultrasonic technique shall be:

At least 70% of the head;

At least 60% of the web;

The area of the foot to be tested shall be as shown in Figure 1.


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figure1 Area to be tested in rail foot shadow

6.12 Surface quality

6.12.1 The rail surface shall be free of crack, fold and transverse guide marks. The imperfections that complywith the criteria below is permitted:

6.12.1.1 The longitudinal hot formed scratches, longitudinal cracks, scale which depth not exceed 0.5mm.

6.12.1.2 The depth of longitudinal and transverse cold formed scratches do not larger than 0.4mm for the railrunning surface and underside of foot; 0.5mm for the rest of rail.

6.12.2 Drilled holes and rail ends shall be deburred and without surface lamination and crack.

6.12.3 Any bulge on running surfaces, rail foot surfaces and 1m from end of the rail which affects fishingsurfaces shall be dressed.

6.12.4 Surface imperfections can be dressing by grinding. Dressing shall along the longitudinal direction andthe dressing width shall not less than 5 times of dressing depth. The dimensions of rails after dressing shallcomply with requirements of Table 1. The rail microstructure shall not be affected by the operation and thework is contour blended.

6.13 Residual stress

The maximum longitudinal residual stress in the foot shall not great than 250MPa.

6.14 Fatigue

For a total strain amplitude of 1350 , the fatigue life ( i.e circle times when the specimen completelyseparation ) of each specimen shall be greater than 5 10 6 cycles.

6.15 Fracture toughness

The fracture toughness K 1C of rails tested at -20 the minimum single value shall be 26MPam1/2 and the

minimum mean value shall be 29MPam 1/2 .

7 Test methods

7.1 Test items, sampling position, sampling numbers and test methods shall be as given in table 6.

Table6 Test items, sampling position, sampling numbers and test methods

No. Test items sampling position samplingnumbers test methods

1 Dimension 300mm from each rail end Each Gauge in annex C,calipers


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2 Shape End EachfigureC11 figureC4-

1 figureC4-2

3 Chemicalcomposition See figure2 1 / heat GB/T223 GB/T4336

4 Oxygen After vacuum degassed or finished

rail see figure4 1/ lot GB/T223.35

5 Hydrogen 7.2.2 or agreed by purchaser andsupplier 1 or 2 / heat Agree by purchaser and

supplier

6 Macrostructure Any part except mixing zone 1/ heat GB/T226

7 Tensile strength Any rails except mixing zone see

figure2 specimen diameter 10mm1/ heat GB/T228

8 Microstructure See figure2 7.3 GB/T13298

9 Decarburisation See figure3 1/ lot 7.4, GB/T224

10 Non-metallicinclusion Head of rail 1/ lot 7.5

11 Drop-weight teartest Any part except mixing zone 1/ lot 7.6

12 Ultrasonic test Whole length Each YB/T 951

13 Surface quality Whole length Each Visualizing

14 Residual stress 3000mm from each rail end 7.8 Annex D

15 Fatigue 3000mm from each rail end Seefigure 5

7.9 GB/T 3075

16 Fracture toughness 3000mm from each rail end 7.10 GB/T 4161and annex E

38kg/ m and 43 kg/ m rails may not subject to items No. 8, No.9, No.10, No.14, No.15, No.16.

7.2 Chemical composition test

7.2.1 Product analysis can be performed if required by the purchaser. One test piece shall be taken from anyrail of each lot. Test pieces shall be sampled from whole profile of the rail or as shown in figure 2.

7.2.2The hydrogen content of the liquid steel shall be determined each heat when the blooms are not slowlycooled. At least two liquid samples shall be taken from the first heat of any sequence using a new tundishand one from each of the remaining heats and analyzed for hydrogen content. Hydrogen determination shallbe carried out on samples taken from the centre of the rail head. The first sample from the first heat in asequence shall be taken from the last rail rolled by the first bloom of any strand and determined by hydrogendeterminator.


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Figure 2 Location of tensile test piece , microstructure checks and product chemical composition

7.3 Microstructure

The sampling position in the rail head shall be as shown in Figure 2. The test shall be made once per 1000tons or less and there of in accordance with GB/T 13298.

7.4 Decarburization

The testing position in the surface of rail head shall be as shown in Figure 3. The test shall be made tomeasure the depth of closed ferrite network in accordance with GB/T 224.

Figure 3 Range of extent of rail head surface for decarburization checks

7.5 Determination of total oxygen content

The sampling position to determinate total oxygen content shall be as shown in Figure 4.

Figure4 Sampling positions for total oxygen determination


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7.6 Evaluation of nonmetal inclusions

One test piece shall be taken from each lot to evaluate nonmetal inclusions. Test pieces shall be longitudinalcut from head of rails. The surface to be tested shall be 10mm~15mm from running surface and area notless than 200mm 2. The results shall be evaluated by method A of annex A of GB/T 10561.

7.7 Drop-weight test

7.7.1 Test pieces shall be at least 1300mm in length and without defects on surface.

7.7.2 Test temperature shall above 10 . The drop weight tester shall be as that capable of supporting a railon two bears( the span shall be 1000mm), and dropping a weight 1000kg in mass freely on its center from aheight given in Table 7.

Table7 Dropping height

Profiles kg/m 37 38 43 50 60 75

Height (m) 5.55 5.8 6.7 7.7 9.1 11.2

Height of the hammer also can be evaluated by the following formula:

m

r

M

M H

150

H Dropping height m

Mr liner mass of the rail kg

Mm weight of the hammer kg

7.8 Residual stress in rail foot

For residual stress tests there shall be 3 sample rails, which be removed from finished roller straightenedrails, and test pieces shall be taken at least 3000mm from each rail end. Test pieces from the rail sectionshall be 1000mm in length. The residual stresses in the rail foot shall be determined in accordance withannex D. Tests shall be make every 2 years or great changes happen in manufacture process.

7.9 Fatigue test

There shall be 3 sample rails removed from finished roller straightened rails from different heat and cast, and2 specimens shall be taken at least 3000mm from each rail end. The specimen dimension and samplingposition shall be as shown in Figure5. Tests shall be make every 5 years or great changes happen inmanufacture process.


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8.3 Retest and justification

8.3.1 When the initial test of rails unqualified, retest and justification shall comply with the followingrequirements.

8.3.1.1 Retest of chemical composition

The rails shall be rejected if the chemical composition unqualified.

8.3.1.2 Retest of tensile test

If any test result fails to meet the requirements, then two tests shall be performed on samples from otherrails of the same heat. One sample shall be taken from the rails of same strand with the original sample, theother sample shall be taken from different strands. The rails of this heat shall be accepted when the resultsof the tests both in accordance with this standard.

If the retest results both not in accordance with this standard, further test shall be made. That is rails fromone strand shall be rejected when two retest results from one strand unqualified. Should either retest fail thenthe rails shall be progressively tested until acceptable material is found.

8.3.1.3 Retest of decarburization and nonmetallic inclusions

8.3.1.3.1 Decarburization

If the initial test result fails to meet the requirements, then retests shall be performed on samples by heat.One sample shall be taken from two rails of the initial heat and one from each of the remaining heats. Therails of the initial heat shall be accepted when the results of the tests both in accordance with this standard.The rails of the initial heat shall be rejected when one of sample unqualified. The rails of other heats shall beaccepted when the result of the test in accordance with this standard. If the test result fails to meet therequirements then two more samples shall be taken from other two rails of one heat individually. The rails ofthis heat shall be accepted when the results of the tests both in accordance with this standard. The rails ofthis heat shall be rejected when one of the test unqualified.

8.3.1.3.2 Nonmetallic inclusions

If the initial test result fails to meet the requirements, then two tests shall be performed on samples fromother rails of one heat. One sample shall be taken from the rails of same strand with the initial sample, theother sample shall be taken from different strands. The rails of this heat shall be accepted when the resultsof the tests both in accordance with this standard. Rails from one strand shall be rejected when two retestresults from one strand unqualified; Should either retest fail then the rails shall be progressively tested untilacceptable material is found.

8.3.1.4 Macrostructures

8.3.1.4.1 The rails shall be rejected if Hydrogen Flakes appears.

8.3.1.4.2 If the macrostructures initial test result fails to meet the requirements of this standard, the followingmethod shall be used to retest.

Two samples shall be taken from the before and back the sampling position of initial test. One sample shallbe taken from the rails of same strand with the initial sample. The rails of this heat shall be accepted whenthe results of the tests both in accordance with this standard. Should either retest fail then the rails shall beprogressively tested until acceptable material is found.

8.3.1.5 Retest of drop weight test

If the initial test result fails to meet the requirements then one test shall be performed on samples from railsof each heat. Two sample shall be taken from the before and back the sampling position of initial test. One

sample shall be taken from the rails of same strand with the initial sample. The rails of this heat shall beaccepted when the results of the tests both in accordance with this standard. Should either retest fail thenthe rails shall be progressively tested until acceptable material is found.


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9 Brand marks and Certif ication

9.1 Brand marks

9.1.1 Brand marks shall be rolled in relief on one side and in the middle of the webof each rail at least onceevery 4 m, the brand marks on the rails shall be clearly and convex, and shall be 20 mm to 28 mm high,convex height between 0.5mm to 1.5mm.

The brand marks shall include:

a) the identification of the mill;

b) the rail profile identification;

c) the steel grade;

d) the year( the last two figures) and month of manufacture.

9.1.2 Each rail shall be identified clearly by hot stamped(cold stamped is not permitted) on the rail web andeach rail shall be hot stamped at least twice every 25m from the end of 2m. The surface of characters shallhave a flat or radius face, and shall be 10mm~16mm in high, 0.5mm~1.5mm in depth, 1mm~1.5mm in width.

a) the number of the heat;

b) the number of the strand;

c) the number of the sequence (A, B ,C...).

9.1.3 In the event of identification marks having been removed, omitted or requiring alteration, re-identification of such marks shall be made by hot stamped or painted.

9.1.4 After packed up, on one end of rails tags shall be attached or get steel seal which includes profiles,steel grades, heat and length etc.

9.1.5 The rail shall not consignment when no mark or mark cant be clearly identified.

9.1.6 Painting of rails shall be agreed by purchaser and supplier.

9.2 Certification

When specified in the purchase order or contract, a certification shall be furnished, include:

a name of manufactory

b name of purchaser;

c the rail profiles drilled rails and welded rails

d the number of contract;

e the number of this standard;

f the steel grades

g quantity, the length of rail;

h heat

i all the test results specified in this standard


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j ex-factory date.

10 Quality assurance system

10.1 Quality system

Quality system that certified and verified by national certification body and in accordance with GB/T19001shall be applied by the supplier.

10.2 Period of quality assurance

10.2.1 Supplier shall assurance that the rails are free of harmful defects form manufacture date N to 31thDecember of N+5. In the meantime, if the rails due to fracture or other defects cannot be applied, supplierand purchaser shall check the product, to carry out laboratory test when necessary.

10.2.2 In case of dispute, the arbitration organization shall be agreed between supplier and purchaser.


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Annex A

Normative

Rail profiles

A.1 The rail profiles dimensions of 38kg/m 75kg/m is as given in figure A.1 A.5 The theoretical weight of

rail and metal distribution see table A.1 table A.2

Figure A.1 Rail profile 38kg/m


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Table A.1 Calculate data of rail

Rail stylekg/m

Sectionarea

cm 2

Center ofgravity frombottom of

rail

cm

Center ofgravity fromends of rail

cm

momentinertia ofHorizontal

axis cm4

Moment inertiaof vertical axis

cm 4

Cross-sectioncoefficient

of bottom

cm 3


of top

cm 3


of bottomside edge

cm 3

38 49.5 6.67 6.73 1204.4 209.3 180.6 178.9 36.7

43 57.0 6.90 7.10 1489.0 260.0 217.3 208.3 45.0

50 65.8 7.10 8.10 2037.0 377.0 287.2 251.3 57.1

60 77.45 8.12 9.48 3217 524 369.0 339.4 69.9

75 95.037 8.82 10.38 4489 665 509 432 89

Table A.2 Metal distribution of rail

Profile kg/m 38 43 50 60 75

Rail head 43.68 42.68 38.68 37.47 37.42

Rail web 21.63 21.31 23.77 25.29 26.54Metal distribution of rail

Rail foot 34.69 35.86 37.55 37.24 36.04


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Annex B

(Normative)

Technical requirements of End hardened rails

B.1 Shapes and dimensions of Hardened Region on Rail Sections

The shapes and dimensions of the hardened region in the lateral and longitudinal sections of a rail shall beas specified in Figure B1.

Dimensions in millimeters

a) Hardened region in the lateral sections b Hardened region in the longitudinal sections

Figure B1 Shapes and Dimensions of Hardened Region

B.2 Hardness of Hardened Region of Rail Section

B.2.1 Surface hardness of Rail head top

The surface hardness of the stationary hardened part at the rail head top of U74 U71Mn shall beHBW302~388 HRC32.5~42.0

B.2.2 The hardness of hardened depth of rail section

The hardness of stationary hardened part of the rail 7mm from the centre of head top shall HB280HRC28.0 .

B.2.3 Hardness distribution of hardened region in the longitudinal sections and rail section

a) The hardness of the stationary hardened part of the rail shall decrease gradually inward from the railsurface, and there shall be no sudden change and discontinuity;

b) The hardness of the transition part of the rail shall decrease gradually in proportion as the hardeneddepth decreases.

B.3 Microstructure of hardened layer

Microstructure of hardened layer shall be shred pearlite and a little ferrite, but no martensite and bainite.

B.4 Appearance

The rail shall be free from injurious defects such as quenching cracks, flaws and distorsions.

B.5 Tests

B.5.1 Surface hardness test on head top of rail


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The test shall be located in a place approximately 50mm from the quenched end and the surface layer shallbe ground. The test method shall be in accordance with GB/T 231.1 or GB/T 230.

B.5.2 Quenching equipments

The quenching equipments shall work well before quenching so that the shape of the harden layer is properand without quenching cracks. If the quenching equipments appear abnormal phenomena during the

manufacture process, the equipments shall be adjusted immediately and test the longitudinal test piecesuntil the test results qualified.

B.5.3 Test on shapes of hardened region of rail sections

B.5.3.1 Test rails

From the same profile, grade and heat treatment conditions, take one rails 500mm in length to heat treatunder the same conditions as the products.

B.5.3.2 Test pieces

Test pieces shall be made by the following requirements:

a Test piece of the lateral section of the rail

Cut off the cross-section sample from approximately 20mm the heat-treated end of the test rail and grind itsinside surface to finish

b Test piece of the longitudinal section of the rail

Split the head of the rail which is the remainder of the test rail from which the lateral section test piece hasbeen cut off, longitudinally along the center line of the width of head into two, and then grind the longitudinalsection of either portion to finish.

B.5.3.3 Test methodThe ground test pieces shall be etched by solution of 5% nitric acid and alcohol to reveal the shape ofhardened layer.

B.5.4 Hardness distribution test of hardened region of rail section

B.5.4.1 Test rail and test piece

Test rail and test piece shall in accordance with B5.3.1 and 5.3.2.

B.5.4.2 Test method

Test method shall in accordance with GB/T230.

B.5.4.3 Measuring positions

The measuring positions shall be the positions marked with X in figure 2.

B.5.5 Microstructure test

The test pieces shall be taken from the softened part and transition part individually.


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Dimensions in millimeters

Figure B.2 Measuring position of lateral section and longitudinal section of the rail

B.6 Record

The manufacturer of the rail shall test the rail as the requirements of B.5 and supply the results to purchaser.

B.7 Reheat-treated

The manufacturer have right to reheat-treated any unqualified rails but not exceed 2 times. The rails appearsquenching cracks is not permitted to reheat-treated.


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Annex C

Normative

Profile and drilling gauges

Figure C.1 Datum references for tolerances


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Figure number

0 Height, (must not), (must pass ) C7

1 Width of rail head must not must touch C2

1 Rail asymmetry must not must touch C3

2 Inclination of fishing surfaces C4

3 Height of fishplating must not must touch C4

3 Width of rail web must not must touch C5

4 Width of rail foot must not must touch C8

Figure C.2 Datum references for decision


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Figure C.3 Width of rail head


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Figure C.4-1 Rail asymmetry


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Figure C.4-2 Rail asymmetry


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GB 2585 2007

Note:

x1, x2, x3, x4 is distance between rail and guage;

The maximum difference between x1 and x2 is 0.35mm;

The maximum difference between x3 and x4 is 0.35mm;

The total difference is 0.35mm.

Figure C.5 Fishing height and inclination


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Figure C.6 web thickness


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key

1 Maximum

2 Minimum

3 Width of foot/2

4 Tolerance

Figure C.7 Foot toe thickness


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Figure C.8 Height of rail


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Figure C.9 Width of rail foot


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e Web thickness;

TdTolerance of hole diameter;

TcTolerance of hole location;

Td/c Total tolerance of hole diameter and location;

Td/c =2( Td + Td/c )

Figure C.10 Gauge for checking distance between holes and rail end and hole diameter


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Figure C.11 Check on the deviation of rail ends


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Annex D

(normative)

Method for the determination of rail foot surface longitudinal residual str esses

D.1 Procedure

Residual stresses shall be estimated by first attaching an electrical strain gauge on the rail foot surface, thenthe surface to which the gauge is attached shall be progressively isolated from the rail, and the relaxedstrains shall then be used to estimate the original residual stresses.

D.2 Strain gauges and their location

Electrical strain gauges of the encapsulated type shall be used, 3 mm in length with a gauge factor accuracyof better than 1 %.

The strain gauge shall be attached to the surface of the rail foot in order to measure longitudinal strain at thepositions as shown in Figure D.1. The surface of the rail foot and the strain gauge attached shall be preparedin accordance with the recommendations of the strain gauge manufacturer.(Note: Any surface preparationshall not itself result in a change of the residual stresses in the rail foot.) The strain gauges shall locate at thecentre of sample rails 1m in length.

Cut a 2 0 mm 40 mm thick slice from the centre of the rail length (Figure C.2), measure stress value beforecut and after (Cooling properly shall be taken when cutting).The residual stresses shall be calculated fromthe differences between cut before and after, then by multiplying by 2,07 10 5 MPa.

Strain gauge

Figure D.1 Location of strain gauge to measure rail f oot su rface longitudinal residual st resses


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Annex E

(normative)

Test method for the determination of the plane strain fracture toughness ( K1c) of rails

E.1 Test methods

In addition to the requirements in this standard, test shall be performed in accordance with the requirementsof GB/T 4161.

E.2 Test p ieces

B.2.1 The location of the test piece in the rails transverse section is shown in Figure E.1.

E.2.2 The thickness B of all test pieces shall be 25 mm, the width W shall be 40 mm.

E.3 Number of tests

A minimum of 5 tests from each sample shall be performed.

E.4 Test conditio ns

E.4.1 Fatigue pre-cracking shall be carried out in the temperature range + 15 to + 20 using a stressratio in the range 0 + 0,1, cyclic frequency in the range 15 Hz to 120 Hz.The final crack length to testpiece width ratio shall be in the range 0,45 to 0,55 and when the cracks growing to 1,25 mm, Kmax shall bein the range 18 MPa m 1/2 to 22MPa m 1/2 .

E.4.2 The single edge notched bend test piece shall be loaded under displacement control using three pointbending with a loading span ( S ) equal to four times the test piece width ( W).

E.4.3 Tests shall be performed at -20 2, test piece temperature may be measured using a beadless

thermocouple spot welded to the test piece at the location shown in Figure E.2. In order to avoid the front ofcrack bend occur , the notch specified in GB/T 4161 is recommended.

E.5 Analysis of test data

E.5.1 The calculation of KQ shall be in accordance with GB/T 4161. In addition to the requirements of E.5.2to E.5.6, the checks made to establish whether this value is a valid K1c shall be in accordance with GB/T4161.

E.5.2 P max /P Q shall be less than 1,10 for force-crack mouth opening curves where pop-in does not occurbefore the intersection of the curve with the 95 % secant. There shall be no P max /P Q criterion for other typesof curve.

E.5.3 The linearity of force-crack mouth opening curves I a , Ib, IIa and III (see Figure E.3) shall be checked inthe following manner:

Measure the distance ( v1) between the tangent OA and the force-crack mouth opening curve at a constantforce of 0,8 P Q. Measure the distance ( v) between the tangent OA and the force-crack mouth opening curveat a constant force of P Q . For a test result to be valid V1 0,25 V.

E.5.4 The linearity of force - crack mouth opening curves II b and II c (see Figure E.3) shall be checked in thefollowing manner:

Measure the distance between the tangent OA and the force - crack mouth opening curve at constant forcesof 0,8 P Q and P Q recording these values as V1 * and V* respectively.

Measure the crack mouth opening values arising from all pop-ins that occur up to P Q; this is done bymeasuring the horizontal distance travelled along the crack mouth opening axis between the start and finish


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of each pop-in.Sum the values for pop-ins occurring below 0,8 P Q and for those occurring between 0,8 P Q and P Q recording them as V1pi and Vpi respectively.

For a test result to be valid [ V1 *- V1pi] 0,25 [ V* - ( Vpi + V1pi)]

E.5.5 The linearity criterion cannot be applied to force - crack mouth opening curve IV.

E.5.6 For all force - crack mouth opening curves the KQ value shall be subjected to the validity check that thetest piece thickness (B) and crack length (a) are equal to, or greater than, the value of 2,5 ( KQ/R p0,2 )2, where

Rp 0,2 is the 0,2 % proof stress at the fracture test temperature of - 20 .

E.6 Reporting of r esults

All measurements required to calculate the test result and to show that the test conditions were as specifiedin the test procedure shall be recorded.

All results shall be reported as either KIc values*QK values or KQ values; where

*QK values are those KQ

values which failed the validity criteria due only to one or more of the following:

1) P max /P Q > 1,1;

2) Exceed the 2,5 ( KQ/R p0,2 )2 criterion;

3) Crack mouth opening displacement - force relationship.

The mean and standard deviation of both KIC and*QK results shall be recorded in accordance with table E.1.

Table E.1 Mean and standard deviation of K 1C and K Q*

grade

0.2

-20

(MPa)

Mean of K 1C

(MPa m 1/2 )

K1C

Measurement

times

standarddeviation

(MPa m 1/2 )

Mean of K Q

(MPa m 1/2 )

KQ

Measurement

times

standarddeviation

(MPa m 1/2 )

The value to be used for the acceptance criteria is that of the mean KIC and shall be based on a minimum of

five KIC values. When five KIC values have not been obtained any*QK values shall be included with any KIC

values in the mean value to be used for the acceptance criteria. In this event the number of test results shallbe at least ten.

All values of KIC and*QK shall be accordance with 6.15.


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Dimensions in millimetres

Key

1 Notch machined in this face

2 Section through rail head

3 Letter H to be stamped on end face of test piece as shown

B = 25

W = see B.2.2

For all other test piece proportions

see ASTM E399

Figure E.1 Location and section of f racture toughness test pi eces


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Dimensions in millimetres

Key

1 Notch

2 Thermocouple to be placed in the shaded zone

3 Fatigue crack tip

Figure E.2 Location of thermocouple on fracture toughness specimens

Key

1 Force, P

2 Crack mouth opening displacement (v)

Figure E.3 Force - Crack mouth opening curves


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Annex F

(normative)

Standard diagrams for macrostructure of rails

F.1 Cross section of rail include 3 parts: head, wed, root, see figure F.1.

F.2 Failure conditions of macrostructure see table F.1.

Figure number Failure conditions

Figure F.2 F.3 Hydrogen flakes

Figure F.4 F.5 Shrinkage

Figure F6 F.7 Web centre cracks extend to head or root

Figure F.8 F.9 Cracks more than 64mm in length

Figure F.10 Web centre cracks scattered extend to head or root

Figure F.11 Segregation scattered extend to head or root

Figure F.12 Subsurface porosity

Figure F.13 Segregation more than 13mm in length and more than 6mm in widthextend to head or root

Figure F.14 Head cracks more than 3mm developed from radial cracks, middlecracks and zigzag cracks

Figure F.15 Other defects (such as slag, refractory) cause rails failure early

Figure F.1 Cross section of rail


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Figure.2 Hydrogen flakes


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Figure.3 Shrinkage


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Figure.4 Shrinkage


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Figure.5 Shrinkage


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Figure.6 Web centre cracks extend to head or root


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Figure.7 Web centre cracks extend to head or root


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Figure F.8 Cracks more than 64mm in length


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Figure F.9 Cracks more than 64mm in length


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Figure F.11 Segregation scattered extend to head or root


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Figure F.12 Subsurface porosity


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Figure F.13 Segregation more than 13mm in length and more than 6mm in width extend to head or root


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Figure F.14 Head cracks more than 3mm developed from radial cracks, middle cracks and zigzag cracks


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Figure F.15 Other defects (such as slag, refractory) cause rails failure early

gb 2585 - 2007 hot-rolled steel rails for railway

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