RAIL SPECIFICATIONS AND RAIL CORROSION RAIL SPECIFICATION Standard

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RAIL SPECIFICATIONS AND RAIL CORROSION

RAIL SPECIFICATIONS AND RAIL CORROSION

RAIL SPECIFICATION • Standard Specifications for Flat Bottom Rails initially adopted in 1934 •

RAIL SPECIFICATION • Standard Specifications for Flat Bottom Rails initially adopted in 1934 • Revised in 1939, 1955, 1958, 1960 1964, 1988, 1996 • Latest version : T-12 (2009) • Provides specifications for rails having UTS of 880 MPa, 1080 MPa CR and 1080 MPa HH • Specifies Niobium (NB), Vanadium (VN), Copper Molybdenum (CM), Nickel Chromium Copper (NC) rails

Rail Sections • • IRS 52 kg/m UIC 60 kg/m ZU 1 -60 Profile

Rail Sections • • IRS 52 kg/m UIC 60 kg/m ZU 1 -60 Profile (73 kg/m) 136 RE 14 (68 kg/m)

Iron from Iron Ore. . • Iron ore mixed with carbon (coke) & a

Iron from Iron Ore. . • Iron ore mixed with carbon (coke) & a flux (lime-stone) and mixture heated in a blast furnace. • Carbon (Coke) burns to produce carbon monoxide (CO) & heat. • CO : highly reducing gas which reduces iron oxide to iron. • Other impurities are absorbed by flux to form slag which being lighter than iron floats on the surface. Slag also protects iron from further re-oxidation. • Molten iron is tapped from blast furnace & cast into pigs. • This called Pig Iron & process called smelting of iron ore.

MANUFACTURING PROCESS Ø To convert pig iron into steel, various methods: – Bessemer Process,

MANUFACTURING PROCESS Ø To convert pig iron into steel, various methods: – Bessemer Process, – Open Hearth Process, – Basic oxygen method & – Electric Arc Furnace Method Ø Steel to be manufactured using Basic oxygen method or Electric Arc Furnace Method (with secondary ladle refining & vacuum degassing) Ø Basic Oxygen Method is being used in Bhilai Steel Plant for manufacture of rails.

CASTING • INGOT CASTING: liquid steel poured in ingot moulds of Cast Iron. Defects

CASTING • INGOT CASTING: liquid steel poured in ingot moulds of Cast Iron. Defects viz piping, blow-holes, segregation, columnar structure & internal fissures present in Ingots. not used now. • CONTINUOUS CASTING process : to be adopted – no interruption to flow of liquid steel into the moulds and strands – inter-mixing of some liquid steel from the two successive casts is ensured – Cleaner steel – Small and more uniformly distributed inclusion – No Reheating is required. – Economical

CONTINUOUS CASTING • This process comprises the direct solidification of liquid steel into a

CONTINUOUS CASTING • This process comprises the direct solidification of liquid steel into a solid bloom which is continuously extracted from the casting machine and cut into the required length • The cross sectional area of bloom should not be less than ten times the rail section to be produced

Bloom

Bloom

Structures of Steel • Austenite: As liquid metal from blast furnace solidifies, it takes

Structures of Steel • Austenite: As liquid metal from blast furnace solidifies, it takes up Gamma format (temp of 910 deg, crystalline structure transformed into Gamma iron) it can take upto 1. 7% solid carbon into solution. Iron form called Austenite. • Perlite: On further, cooling, Austenite itself transforms into Alpha Iron, a low carbon content phase. (Pure iron exists at room temp in crystalline form known as Alpha Iron) & a lameller structure called as Perlite. (Desired in Rail manufacturing) • Martensite: when hot metal is rapidly quenched, carbon atoms do not have sufficient time to combine with iron atoms hence formation of Perlite is not possible. Surplus Carbon atoms becomes trapped in crystalline structure & distort it. Resultant structure is extremely hard/brittle material known as Martensite.

Classification of Rails • Prime Quality Rails – Class ‘A’ Rails – Class ‘B’

Classification of Rails • Prime Quality Rails – Class ‘A’ Rails – Class ‘B’ Rails v. The classification is based on the tolerance in end straightness • Industrial Use (IU) Quality Rails v. Based on tolerances in sectional dimensions and end straightness

CHEMICAL COMPOSITION OF RAIL STEELS Si P (Max. ) Al (Max. ) Others (Max)

CHEMICAL COMPOSITION OF RAIL STEELS Si P (Max. ) Al (Max. ) Others (Max) 0. 030 0. 015 -- 1. 6 ppm Grade C 880 0. 600. 800. 10 -0. 50 1. 30 1080 Cr 0. 600. 800. 50 -1. 10 1. 20 0. 025 0. 004 0. 20 Mo+. 8 -1. 2 Cr+. 2 V 0. 600. 800. 10 -0. 50 1. 30 0. 030 0. 015 -- 1080 HH Mn S (Max. ) Hydrogen Content in Liq Steel (Max. )

MECHANICAL PROPERTIES OF RAIL STEELS Grade Yield Running Elongation UTS Strength surface (min) hardness

MECHANICAL PROPERTIES OF RAIL STEELS Grade Yield Running Elongation UTS Strength surface (min) hardness (Percent) (MPa) (Mpa) (BHN) 880 460 Min 260 1080 Cr 1080 560 320 -360 9. 0 1080 HH 1080 460 340 -390 10. 0 The Chemical composition of NB, VN, CM & NC rails has also been given in the specs.

EFFECT OF DIFFERENT ELEMENTS CARBON (C) • INCREASES – UTS – YIELD POINT –

EFFECT OF DIFFERENT ELEMENTS CARBON (C) • INCREASES – UTS – YIELD POINT – HARDNESS BUT • DECREASES – DUCTILITY

EFFECT OF DIFFERENT ELEMENTS CHROMIUM (Cr) • INCREASES UTS/hardness • If more than 2%

EFFECT OF DIFFERENT ELEMENTS CHROMIUM (Cr) • INCREASES UTS/hardness • If more than 2% difficult to weld. SILICON (Si) • USED AS DEOXIDISING AGENT (removes extra oxygen=killing) • INCREASES THE DEPTH OF HEAT TREATMENT • EXCESS LEADS TO BRITTLENESS, • Preferred deoxidizing agent compared to AL, as oxides of SI which solidify as inclusions in solidified steel are less harmful than AL during subsequent service life.

EFFECT OF DIFFERENT ELEMENTS ALUMINIUM (AL) (max 0. 015%) • USED AS DEOXIDISING AGENT

EFFECT OF DIFFERENT ELEMENTS ALUMINIUM (AL) (max 0. 015%) • USED AS DEOXIDISING AGENT (removes extra oxygen=killing) • But SI is preferred deoxidizing agent compared to AL, as oxides of SI which solidify as inclusions in solidified steel are less harmful than AL during subsequent service life.

EFFECT OF DIFFERENT ELEMENTS • PHOSPHORUS (P): 0. 030% (MAX) • LEADS TO COLD

EFFECT OF DIFFERENT ELEMENTS • PHOSPHORUS (P): 0. 030% (MAX) • LEADS TO COLD SHORTNESS i. e. liable to crack when cold worked • INCREASES UTS, YIELD POINT, HARDNESS • INCREASES BRITTLENESS • REDUCES IMPACT STRENTH DUE TO INCREASED GRAIN SIZE • Its basically a impurity from naturally occurring iron ore. Difficult to eliminate altogether in smelting/refining process.

EFFECT OF DIFFERENT ELEMENTS • SULPHUR (S) (0. 30% max) : CAUSES – SEGREGATION

EFFECT OF DIFFERENT ELEMENTS • SULPHUR (S) (0. 30% max) : CAUSES – SEGREGATION – HOT SHORTNESS i. e. liable to crack when hot – EXCESS CAUSES POROSITY DURING WELDING – Highly injurious impurity (from naturally occurring iron ore), Manganese is added to form Manganese Sulfide (Mn. S), which floats off in slag.

EFFECT OF DIFFERENT ELEMENTS • HYDROGEN (H 2) 1. 6 ppm Max. – Basically

EFFECT OF DIFFERENT ELEMENTS • HYDROGEN (H 2) 1. 6 ppm Max. – Basically a impurity. – H 2 atoms are smallest, move freely by diffusion within cavities of liquid & solidified steel in micro/submicro-scopic level. H 2 molecules exert increasing pressure on metal surrounding cavities. – CAUSES hydrogen FLAKES/SHATTER CRACKS – Makes steel brittle – Higher strength steels more prone for hydrogen embrittrilment than low strength steels. – Higher strength wear resistance steel requires more careful control procedure to reduce risk of fractures. – CONTROLLED COOLING ALLOWS HYDROGEN TO DIFFUSE OUT

EFFECT OF DIFFERENT ELEMENTS MANGANESE • USE AS DEOXIDANT • PREVENTS IRON SULPHIDE FORMATION

EFFECT OF DIFFERENT ELEMENTS MANGANESE • USE AS DEOXIDANT • PREVENTS IRON SULPHIDE FORMATION THUS REDUCES HOT SHORTNESS. • IF >0. 8% INCREASES UTS WITHOUT LOSS OF DUCTILITY • INCREASES WELDABILITY • IF BEYOND 2% : BAINITIC & MERTENSITIC STEELS ARE FORMED • Advantageous as it increases hardness of steel thereby improving its strength and toughness.

EFFECT OF DIFFERENT ELEMENTS • OXYGEN • DECREASES – DUCTILITY – IMPACT RESISTANCE •

EFFECT OF DIFFERENT ELEMENTS • OXYGEN • DECREASES – DUCTILITY – IMPACT RESISTANCE • INCREASES HARDNESS SLIGHTLY • NITROGEN – Basically a impurity. – Nitrogen dissolves in liquid steel & due to its small atomic size, atoms are located between iron & carbon atoms making bulk of steel. – INCREASES strength &HARDNESS but reduces ductility. – LEADS TO AGE HARDENING

BRAND MARK The brand mark shall be rolled in relief at least every 3

BRAND MARK The brand mark shall be rolled in relief at least every 3 m, and shall include • The rail section • The grade of steel • Grade 880 - 880 • Grade 1080 HH - 1080 HH • Grade 1080 Cr - 1080 CR • Grade 880 Cu-MO - 880 CM • Grade 880 Ni Cr Cu - 880 NC • Grade 880 Vanadium - 880 VN • Grade 880 Niobium - 880 NB

BRAND MARK • Identification mark of the manufacturer • Month (using roman numbers) and

BRAND MARK • Identification mark of the manufacturer • Month (using roman numbers) and last two digits of year of manufacture • Process of steel making • Basic oxygen – O • Electric - E

MARKING ON RAIL • Hot stamping at least every 4. 0 m on web

MARKING ON RAIL • Hot stamping at least every 4. 0 m on web • Cast No. with letter ‘C’ • Number of the strand. • For rails from change over bloom, cast number should be the preceding cast number with prefix letter ‘B’ • Cold punching on one of the end faces • Inspecting Agency Id and Group ID • Shift No in which product inspected • Date of Inspection

MARKING ON RAIL • For IU rail, the letter ‘IU’ to be stamped on

MARKING ON RAIL • For IU rail, the letter ‘IU’ to be stamped on both end faces of each rail • Rails shall be painted as per colour code given in Appendix-IV of the Specifications to distinguish grade, class, length and other special requirements

COLOUR CODING Prime 13 m IU 13 M Prime 12 m Prime 11 m

COLOUR CODING Prime 13 m IU 13 M Prime 12 m Prime 11 m IU 11 M Prime 10 m REJECTED

SECTIONS AND DIMENSIONS • • • Tolerances in sectional Dimensions Length End Squareness End

SECTIONS AND DIMENSIONS • • • Tolerances in sectional Dimensions Length End Squareness End Straightness Surface defects

MEASUREMENTS DIMENSIONAL ACCURACY – PRIME QUALITY RAIL – ACTUAL WEIGHT WITHIN +1. 5%/ –

MEASUREMENTS DIMENSIONAL ACCURACY – PRIME QUALITY RAIL – ACTUAL WEIGHT WITHIN +1. 5%/ – 0. 5% 0 F CALCULATED WEIGHT (SAMPLE PIECE SHOULD BE ATLEAST 300 MM IN LENGTH) – OVERALL HEIGHT +0. 8 MM AND – 0. 4 MM – WIDTH OF HEAD ± 0. 5 MM(MEASURED 14 MM BELOW THE RAIL HEAD)

MEASUREMENTS DIMENSIONAL ACCURACY – PRIME QUALITY RAIL – WIDTH OF FLANGE • ± 1.

MEASUREMENTS DIMENSIONAL ACCURACY – PRIME QUALITY RAIL – WIDTH OF FLANGE • ± 1. 0 MM FOR SECTION LESS THAN 60 KG. /M. • +1. 2 MM/-1. 0 MM FOR SECTIONS 60 KG/M AND ABOVE – WEB THICKNESS +1. 0 MM/ -0. 5 MM – measured at the point of min thickness – VERTICALITY/ASYMMETRY +1. 2 MM/-1. 2 MM – BOTTOM OF THE RAILS SHOULD BE FLAT BUT CONCAVITY OF 0. 4 MM IS PERMITTED.

MEASUREMENTS DIMENSIONAL ACCURACY – PRIME QUALITY RAIL – STRAIGHNESS CHECKED ON 1. 5 M.

MEASUREMENTS DIMENSIONAL ACCURACY – PRIME QUALITY RAIL – STRAIGHNESS CHECKED ON 1. 5 M. STRAIGHT EDGE SHALL BE LIMITED TO 0. 7 MM, entire length – END STRAIGHTNESS • CHECKED BY 2. 0 M. STRAIGHT EDGE FOR CLASS A RAILS TO BE LIMITED TO 0. 4 MM VERTICAL ( UP SWEEP), DN SWEEP NIL AND 0. 5 MM HORIZONTAL • BY 1. 5 M STRAIGHT EDGE FOR CLASS B RAILS TO BE LIMITED TO 0. 5 MM VERTICAL ( UP SWEEP), DN SWEEP NIL AND 0. 7 MM HORIZONTAL

Online Top Flatness Measurement

Online Top Flatness Measurement

Online Straightness Measurement

Online Straightness Measurement

TESTING OF RAILS • QUALIFYING TESTS – Residual Stress Measurement – residual tensile stress

TESTING OF RAILS • QUALIFYING TESTS – Residual Stress Measurement – residual tensile stress anywhere < 190 MPa – Fracture Toughness Measurement – Fatigue Test – sample should endure 10 million cycle at specified strain level • THESE WILL BE CARRIED OUT FOR EACH SECTION, GRADE AND CLASS OF RAIL WHENEVER THERE IS A CHANGE IN MANUFACTURING PROCESS OR AT STIPULATED FREQUENCY

TESTING OF RAILS FREEDOM FROM DEFECTS – FREE FROM DEFECTS, CRACKS, PIPING ETC. –

TESTING OF RAILS FREEDOM FROM DEFECTS – FREE FROM DEFECTS, CRACKS, PIPING ETC. – ULTRASONIC TESING – EDDY CURRENT TESTING

ULTRA SONIC TESTING MACHINE • FOR DETECTING INTERNAL DEFECTS • 13 PIEZO-ELECTRIC PROBES •

ULTRA SONIC TESTING MACHINE • FOR DETECTING INTERNAL DEFECTS • 13 PIEZO-ELECTRIC PROBES • DIFFERENT LOCATIONS OF DEFECTS MARKED BY DIFFERENT COLOUR

RAIL MANUFACTURING 3*75 T/Hr BLOOM REHEATING FURNACES RAIL STRAIGHTENING MACHINE LASER STRAIGHTNESS MEASUREMENT SYSTEM

RAIL MANUFACTURING 3*75 T/Hr BLOOM REHEATING FURNACES RAIL STRAIGHTENING MACHINE LASER STRAIGHTNESS MEASUREMENT SYSTEM 950 MM ROUGHING STAND 800 MM 3 HI INTERMEDIATE STANDS PRECAMBERING & WALKING BEAM COOLING BED EDDY CURRENT TESTING MACHINE AUTOMATIC STAMPING MACHINE ULTRASONIC TESTING MACHINE ONLINE ULTRASONIC TESTING MACHINE 850 MM FINISHING STAND HOT SAWS

EDDY CURRENT TESTING • FOR DETECTING SURFACE DEFECTS AT FOOT, RAIL TOP AND SIDES

EDDY CURRENT TESTING • FOR DETECTING SURFACE DEFECTS AT FOOT, RAIL TOP AND SIDES OF RAIL HEAD • USES EDDY CURRENT LOOPS GENERATED ON RAIL SURFACE BY PROBE WINDINGS

RAIL MANUFACTURING 3*75 T/Hr BLOOM REHEATING FURNACES RAIL STRAIGHTENING MACHINE LASER STRAIGHTNESS MEASUREMENT SYSTEM

RAIL MANUFACTURING 3*75 T/Hr BLOOM REHEATING FURNACES RAIL STRAIGHTENING MACHINE LASER STRAIGHTNESS MEASUREMENT SYSTEM 950 MM ROUGHING STAND 800 MM 3 HI INTERMEDIATE STANDS PRECAMBERING & WALKING BEAM COOLING BED AUTOMATIC STAMPING MACHINE EDDY CURRENT TESTING MACHINE ONLINE EDDY CURRENT TESTING MACHINE 850 MM FINISHING STAND HOT SAWS

Testing of rails ACCEPTANCE TESTS – – – – Chemical Analysis Tensile Tests Sulphur

Testing of rails ACCEPTANCE TESTS – – – – Chemical Analysis Tensile Tests Sulphur Print – macrographic defect Hardness Test Falling Weight Test – fracture under std fall Hydrogen content Inclusion Rating Level

RAIL STRESSES

RAIL STRESSES

Stresses in Rail • Residual Stress • Flexural stress • Thermal stress • Contact

Stresses in Rail • Residual Stress • Flexural stress • Thermal stress • Contact stress

Typical Values Adopted on IR

Typical Values Adopted on IR

HANDLING OF RAILS

HANDLING OF RAILS

HANDLING OF RAILS: MAIN CONSIDERATIONS • 90 UTS RAIL ARE HARDER AND MORE BRITTLE

HANDLING OF RAILS: MAIN CONSIDERATIONS • 90 UTS RAIL ARE HARDER AND MORE BRITTLE COMPARED TO 72 UTS RAIL, DUE TO HIGH CARBON CONTENT – Min elongation - 90 UTS – 10%, 72 UTS – 14% • 90 UTS RAIL ARE HIGHLY NOTCH SENSITIVE – Notch of even 0. 25 mm may cause fracture • RAIL SHOULD BE HANDLED AS PER ‘GUIDELINE FOR HANDLING OF RAIL – NOV, 2006’ issued vide Railway Board’s letter No. Track/21/98/0908/7 dated 30 -10 -2006

HANDLING OF RAILS: MAIN CONSIDERATIONS • • • PROTECTION OF STRAIGHTNESS AVOIDING POINT LINE

HANDLING OF RAILS: MAIN CONSIDERATIONS • • • PROTECTION OF STRAIGHTNESS AVOIDING POINT LINE LOADING PROTECTION OF RAIL SURFACE PREVENTION OF METALLURGICAL DAMAGE PROTECTION FROM CONTACT WITH INJURIOUS SUBSTANCES • MINIMISING DANGER TO PERSONNEL

Handling and Stacking of rails • The damage to rails including formation of dent/deformation

Handling and Stacking of rails • The damage to rails including formation of dent/deformation at rail foot can be detected by: • Inspecting rails before laying in track. • Essentially, Rails are to be thoroughly inspected at the level of SSE/P. Way for presence of: • Damages to rails during – Transportation, – Unloading and handling before laying in the track. • In case any damage including dent/deformation is noticed, such rails not to be used in track without removal of damaged portion of rails.

Handling and Stacking of rails • The comprehensive guidelines on handling and stacking of

Handling and Stacking of rails • The comprehensive guidelines on handling and stacking of rails duly approved by Railway Board vide letter dated 30. 10. 2014 issued as “Guidelines for Handling and Stacking of Rails (CT-35), October-2014”. • The items covered are: – Stacking and Handling of rails in rail manufacturing plants, Flash Butt Welding plants and other Bulk Storage locations – Loading and Unloading of Single/Three Rail Panels – Loading and Unloading of long rail panels in EUR rakes – Placement of single rails and welded rail panels on cess – Handling of rails in electrified areas – Handling of rails at airport – Precautions for preventing damage to rail e. g. straightness, rail surface, metallurgical damages etc. – Safety of personnel • Field staff and other agencies involved in handling and laying of rails shall be sensitized for strict compliance of these guidelines to avoid damage to rails during handling and stacking in the field.

HANDLING OF 90 UTS RAILS • LOCALISED POINT/ LINE CONTACT SHOULD BE AVOIDED DURING

HANDLING OF 90 UTS RAILS • LOCALISED POINT/ LINE CONTACT SHOULD BE AVOIDED DURING STACKING • STACKING SHOULD BE DONE ON FIRM SURFACE, WITH SUITABLY PLACED SPACERS/ DUNNAGE • ON GROUND, RAILS SHOULD REST ON ITS FOOT ON CLOSELY SPACED SUPPORTS • PROPER SLINGING DURING LOADING OPERATION – SPACING BETWEEN LIFTING POINTS SHALL NOT EXCEED 6. 5 m – OVERHANG NOT TO EXCEED HALF THE DISTANCE BETWEEN LIFTING POINTS DURING HANDLING • USE OF ROUND LINK CHAIN SLING TO BE AVOIDED • WITH CONVENTIONAL SLINGS, FABRIC SLEEVE SHOULD BE USED

HANDLING OF 90 UTS RAILS • NO DENT MARK SHOULD BE FORMED ON RAIL

HANDLING OF 90 UTS RAILS • NO DENT MARK SHOULD BE FORMED ON RAIL SURFACE • HAMMERING, CHISELING OR PUNCH MARKING MUST BE AVOIDED • LOCALISED HEATING TO BE AVOIDED • FLAME CUTTING – Flame cut joint not to be kept in track – During flame cutting, a min of 100 mm length on either side pre-heated to 250 -300 deg C • HOLES TO BE AVOIDED

HANDLING OF 90 UTS RAILS • PROPER UNLOADING OF SINGLE/ 3 -RAIL AND LONG

HANDLING OF 90 UTS RAILS • PROPER UNLOADING OF SINGLE/ 3 -RAIL AND LONG PANELS • LONG PANELS TO REST ON FOOT • ON GIRDER BRIDGES, RAIL SHOULD BE SUPPORTED ON BRIDGE TIMBER TO AVOID SAGGING • TO BE PROTECTED FROM CORROSION • CONNECTION OF SIGNALLING WIRES – ‘Guidelines for using weld material for track circuit application’ – ref STS/E/Exothermic weld dt 03. 06. 2010

RAIL CORROSION

RAIL CORROSION

Corrosion - General • Types of Corrosion – General Corrosion – Pit Corrosion •

Corrosion - General • Types of Corrosion – General Corrosion – Pit Corrosion • Why Rails Corrode? – General Phenomenon – Iron converts into more stable form of Iron oxides – Corrosion Related to Toilet Droppings • Vulnerable Locations for Corrosion – Approach to major yards – Coastal area

Causes of Corrosion • • Metallurgy of Rails Night Soil Droppings Retention of droppings

Causes of Corrosion • • Metallurgy of Rails Night Soil Droppings Retention of droppings Current induced corrosion

WEAR DUE TO CORROSION (IRPWM CS 130 DT 16. 11. 2012) • Para 302(1)

WEAR DUE TO CORROSION (IRPWM CS 130 DT 16. 11. 2012) • Para 302(1) (b) (ii) – Corrosion beyond 1. 5 mm in the web and foot may be taken as the criterion – Existence of the localized corrosion such as corrosion pits, specially on the underside of the foot and liner biting etc on rail foot, act as stress raisers for the origin of fatigue cracks and would necessitate renewals

Measures Taken • Corrosion pit of 1. 5 mm may be generated in a

Measures Taken • Corrosion pit of 1. 5 mm may be generated in a very small time (about 2 yr) at vulnerable locations • Painting of Rails by – Bituminous paints – Epoxy based paints – Pure Epoxy coats • Greasing and Sealing by grease graphite • Shifting of liner bite location • Interchanging of rails – However, tensile rail stresses are higher at outside of rail foot

Measures Taken • RDSO have issued detailed instructions on painting in 2006 (Lr No.

Measures Taken • RDSO have issued detailed instructions on painting in 2006 (Lr No. CT/ACP dt. 24. 02. 2006) • Zinc metalising followed by 4 coats of painting ( primer, zinc chromate, 2 coats of aluminium paint) for severe corrosion prone locations, to be identified by CTE • To be done preferably in workshop ( Plant Depot) • Further painting (but no repeat of metalising) to be done at site depending on site condition

Measures Taken • Two coats of Bituminous painting on web and foot on inside

Measures Taken • Two coats of Bituminous painting on web and foot on inside (frequency – once an year) and web, foot and vertical face of head on outside (once in 3 years) • Surface preparation, temperature and humidity important • Frequency to be further decided by zonal Railways • Approved sources of paint are issued every 6 month by RDSO QA(Mechanical) Directorate • Railways have issued instructions through PCE Circulars on the matter

Measures Taken • Development of corrosion resistant rails – Cu-Mo Rails - extended trial

Measures Taken • Development of corrosion resistant rails – Cu-Mo Rails - extended trial (2009) for 1000 MT – NCC Rails – extended trial (2009) for 10000 MT • Use of liner free fastenings

IRPWM Correction Slip (#124 dt. 14. 02. 2011) para 250. • Corrosion prone area

IRPWM Correction Slip (#124 dt. 14. 02. 2011) para 250. • Corrosion prone area and severe corrosion prone area to be identified by PCE/ CAO/con • Corrosion prone areas - Measurement of corrosion once an year, every 100 sleeper in the specified proforma • Bituminous painting – In corrosion prone area in continuous stretch, in other areas in patches – For new rail – in work shop, old rail – at site – Paint specification (IS: 9862), thickness (2 coats of 100 micron each), cleaning, temperature etc. specified – Liner and ERC also to be painted – Bituminous paint frequency 1 yr (gauge face)/ 3 yr outside • Zinc metalising in severe corrosion prone area, where ever possible, as per RDSO letter

IRPWM Correction Slip (#124 dt. 14. 02. 2011) para. 250. • Greasing and sealing

IRPWM Correction Slip (#124 dt. 14. 02. 2011) para. 250. • Greasing and sealing of liner contact area – Gauge face side - once an year, Non GF – once in 2 yrs • Shifting of liner locations – by pulling back in SWR/ FP track and Di-stressing in LWR track - as per frequency laid down by CTE • Train watering arrangement to be avoided on run through lines, proper drainage to be ensured in station lines

Short Term Measures üIdentification and Monitoring üGreasing and Sealing of liner contact area üShifting

Short Term Measures üIdentification and Monitoring üGreasing and Sealing of liner contact area üShifting of liner bite location üShifting of lavatory chutes in coaches

Long Term Measures ü ü Eco-friendly Toilets in trains Use of corrosion resistant rails

Long Term Measures ü ü Eco-friendly Toilets in trains Use of corrosion resistant rails Use of liner free fastenings Study of phenomenon of corrosion due to human excreta

Bio-digestor -Being installed in 300 coaches in 2012 -13

Bio-digestor -Being installed in 300 coaches in 2012 -13

Need for Revision of Rail Metallurgy. . • 72 UTS rail steel: • Minimum

Need for Revision of Rail Metallurgy. . • 72 UTS rail steel: • Minimum UTS 710 N/mm 2, • Minimum elongation of 14% and • Minimum surface hardness of 220 BHN. • 90 UTS rail steel: • Minimum UTS 880 N/mm 2, • Minimum elongation of 10% and • Minimum surface hardness of 260 BHN. • Rails of higher UTS (90 and above) » Brittle in nature (lesser ductility) » Susceptible to sudden fracture from minor dent/deformation at rail foot edge due to rubbing of rails during unloading and handling of rails at site.

Need for Revision of Rail Metallurgy…. • Higher UTS (90) Rails are used to

Need for Revision of Rail Metallurgy…. • Higher UTS (90) Rails are used to control the wear to meet needs of increased traffic. • More corrosion prone due to increase C. • Sudden fracture being brittle ( % El 10% ). . • Improvement in quality of rail steel : ‒ Improving ductility to reduce sudden fracture. ‒ Improving Corrosion Resistance of Rails ‒ Tackling Heavier Axle Loads

Analysis of Premature Rail/ FB Weld Failures Improper welding 7% Lack of fussion of

Analysis of Premature Rail/ FB Weld Failures Improper welding 7% Lack of fussion of FBW 3% Electric holder arcing/ arcing 19% Metal to metal rubbing/ Dent/ Depression during transportation 31% Manufacturing Defect 7% Loosening of bolts Sharpness of bolt holts 2% 1% Unusul impact 10% Gass cut holes/ pre Abnormal Torsional force existing cracks 3% 1% Corrosion 11% Presence of shear Crack 5%

Development of New Rail steel Metallurgies • In order to maximise the service life

Development of New Rail steel Metallurgies • In order to maximise the service life of rails, sustained efforts are being made for improvement in quality of Rails by developing: – Micro-alloyed corrosion resistant rails: Nickel-Chromium. Copper and Copper-Molybdenum – Micro-alloyed High strength Rails Vanadium & Niobium Rails. – Higher UTS 1080 grade Cr-V rails for higher axle loads – New improved rail steel having enhanced fracture toughness and ductility, reduced fatigue crack growth rate and improved weldability. • Under Development

NEW PRODUCTS at SAIL – Niobium micro alloyed rails. – Copper Molybdenum corrosion resistant

NEW PRODUCTS at SAIL – Niobium micro alloyed rails. – Copper Molybdenum corrosion resistant rails. – High conductivity rails for metro rails. – Thick web asymmetric rails Zu 1 -60 for switches. – Long Rail welded panels upto 260 m. – Vanadium Micro alloyed high strength rails. – Nickel Copper Chromium high strength corrosion resistant rails.

NIOBIUM RAILS – 692 Tons of Nb rails dispatched to Indian Railways. – Rails

NIOBIUM RAILS – 692 Tons of Nb rails dispatched to Indian Railways. – Rails are under field trial at Kharagpur since 2004. – Micro-alloying with Nb decreases prior austenitic grain size , Pearlite colony size & Inter lamellar spacing. – Improvement in Yield Ratio, Elongation and Fracture Toughness.

NIOBIUM RAILS Chemical Composition ( %) Carbon Manganese Phosphorus 0. 60 -0. 80 Silicon

NIOBIUM RAILS Chemical Composition ( %) Carbon Manganese Phosphorus 0. 60 -0. 80 Silicon 0. 80 -1. 30 Aluminum 0. 030 (max) Niobium Sulphur 0. 030(max) Hydrogen(max) 0. 10 -0. 50 0. 015 (max) 0. 04 (max) 1. 6 ppm Mechanical Properties UTS (Mpa) 880 (min) Yield Strength (Mpa) 540 Elongation (% ) 10. 0 (min) Hardness (BHN) 260

Cu Mo Corrosion Resistant Rail – Rails for coastal areas – Corrosion resistant rails

Cu Mo Corrosion Resistant Rail – Rails for coastal areas – Corrosion resistant rails with Cu-Mo

Cu Mo Corrosion Resistant Rail – Average corrosion resistance index of Cu and Cu-Mo

Cu Mo Corrosion Resistant Rail – Average corrosion resistance index of Cu and Cu-Mo rails found to be 1. 8 and 2. 2 respectively over conventional 90 UTS rail – Cu and Cu-Mo containing 90 UTS rails exhibit much superior corrosion resistance in comparison to conventional 90 UTS rails owing to stable amorphous rust layer formation Total dispatches to Railways: 1035 T

Comparative in-track/ in-service corrosion performance of plain carbon & Cu-Mo rails (a) (b) Photographs

Comparative in-track/ in-service corrosion performance of plain carbon & Cu-Mo rails (a) (b) Photographs showing the comparative rust appearance on plain carbon and Cu. Mo rails after 3 years 6 months of exposure and use in the coastal environment

Vanadium Micro-alloyed High Strength Rails § Conventional 880 MPa pearlitic rails have limitation of

Vanadium Micro-alloyed High Strength Rails § Conventional 880 MPa pearlitic rails have limitation of achieving YS/UTS ratio>0. 52. § Rails are replaced prematurely due to excessive plastic deformation of rail head especially in curved section of the track. § The demand for rails possessing higher strength and YS/UTS ratio is increasing due to stringent service conditions – higher Axle load – higher speeds – higher traffic density – corrosion prone atmosphere § Vanadium micro-alloyed rail (880 grade) is having high yield strength of 630 MPa

Vanadium Micro-alloyed Rails Chemical Composition ( %) Carbon Manganese Phosphorus 0. 60 -0. 80

Vanadium Micro-alloyed Rails Chemical Composition ( %) Carbon Manganese Phosphorus 0. 60 -0. 80 Silicon 0. 80 -1. 30 Aluminum 0. 030 (max) Vanadium Sulphur 0. 025(max) Hydrogen(max) 0. 10 -0. 50 0. 015 (max) 0. 20 (max) 1. 6 ppm Mechenical Properties UTS (Mpa) 880 (min) Yield Strength (Mpa) 630 Elongation (% ) 9. 0 (min) Hardness (BHN) 260

Ni-Cu-Cr Rails Background – Since railway is the cheapest mode of transportation worldwide, rail

Ni-Cu-Cr Rails Background – Since railway is the cheapest mode of transportation worldwide, rail tracks have been laid and used in different geographical situations and frequency. – Moreover, near costal areas and in developing countries due to human excreta, rail tracks faces severe corrosion problem. – Addition of Cr improves strength and Cu & Ni addition improves corrosion resistant properties , Ni also increases toughness of rail steel.

NCC and Cu-Mo Rails • Mechanical properties ( Mean Value of seven Heats) •

NCC and Cu-Mo Rails • Mechanical properties ( Mean Value of seven Heats) • Type of Rail UTS (MPa) YS (MPa) %EL Hardness(BHN) Cu-Mo Rails NCC Rails C-Mn Rails 1119. 1 1040 880 831. 3 683 460 11. 1 12. 03 10. 0 298. 1 314 260 Fracture Toughness & Endurance limits Rail Type K 1 c (MPa m 1/2) Endurance Limit (strain at 10 million cycles) Co-Mo Rails 49. 67* 0. 00152 NCC Rails 35. 52# 0. 00154 C-Mn rails 42* 0. 00135 *At room temperature • • # At -20°C temperature Outcome of lab evaluation: Newly developed NCC & Cu-Mo rails possess • Increased ultimate tensile strength • Almost double the yield strength • Better ductility, Improved hardness • Improved fracture toughness and fatigue strength Field Evaluation: Under field trial in SCR, SWR & WR. Inspection planned for service performance evaluation .

Heavier Axle load Operations • Permissible stresses on 880 grade rails • UTS of

Heavier Axle load Operations • Permissible stresses on 880 grade rails • UTS of Rails : 90 Kg/mm 2 • Yield Strength: (52% of UTS): 46. 8 Kg/mm 2 • Deduction for unforeseen condition: 4. 68 Kg/mm 2 • Deduction for Residual Stress of Rails: 6. 0 Kg/mm 2 • Deduction for Thermal Stresses: 10. 75 Kg/mm 2 • Permissible Limit for Rolling Stock induced Stresses: 25. 25 Kg/mm 2 • Increase in Yield Strength of Rails is economical solution for permitting Higher axle load operations. • Broad parameters adhered in Development of High yield strength Rails Ø Chemical Composition almost similar to 880 Grade Ø Addition of Micro Alloys to improve strength properties Ø Higher Yield Strength/ Ultimate tensile strength Ratio Ø No sacrifice of Ductility Ø No appreciable change in Hardness Ø Endurance at Higher strain Ø Improved Fracture Toughness Ø Improved Wear resistant properties

Niobium, Vanadium & 110 UTS Cr-V Rails • Mechanical properties (Mean Value of Two

Niobium, Vanadium & 110 UTS Cr-V Rails • Mechanical properties (Mean Value of Two Heats) Rail Type UTS (MPa) YS/UTS % Elongation Hardness(BHN) Nb Rails 920. 27 569 0. 618 13. 97 266 V Rails 981 652. 5 0. 665 10. 67 285 110 UTS Rails 1110 738 0. 665 10. 80 345 C-Mn rails 880 460 0. 522 10. 00 260 (Min) • Fracture Toughness, Endurance Limits & Micro Structure Prior austenite grain size (μm) Pearlite colony size, (μm) Inter lamellar spacing (μm) 48. 0* Endurance Limit (strain at 10 million cycles) 0. 00164 20 -30 3 -6 0. 13 -0. 20 V Rails 43. 0* 0. 00174 - - 0. 16 110 UTS Rails 31. 0# 0. 00139 - - - C-Mn rails 42. 0* 0. 00135 25 -65 5 -12 0. 30 -0. 38 Rail Type K 1 c (MPa m½) Nb Rails *At room # At -20°C temperature

Outcome of Lab & Field Evaluations v Nb and V Rails • Lab Evaluation:

Outcome of Lab & Field Evaluations v Nb and V Rails • Lab Evaluation: Ø Ø Finer pearlite inter-lamellar spacing Higher Yield Strength, Higher YS to UTS ratio Improved ductility, Better fracture toughness Superior high cycle fatigue endurance limits • Field Evaluation: Ø Rails laid for field trial in SER, Mid term inspections done in 2011 & 2013. Final inspection planned for service performance evaluation and submission of report. v 110 UTS Rails • Lab Evaluation Ø Ø Higher running surface hardness, Higher tensile strengths (UTS & YS) Higher fracture toughness in comparison of 90 UTS C-Mn Rails Ductility almost at par with normal C-Mn rails. • Field Evaluation Ø Production of 600 T of 110 UTS Rails for limited field trial in progress at Bhilai Steel Plant. Ø Initial limited field trial to be done on routes having axle load operation up to 25 Tonnes. Ø Hatia –Orga section of Ranchi division of South Eastern Railway Ø Performance evaluation for a period of 2 years. Ø Suitability for further higher axle load upto 32. 5 Tonnes will be explored after evaluation of trial results. Ø 200 out of 600 MT of 110 UTS rails rolled in BSP, Bhilai. Further rolling in progress for trials.

Thick Web Asymmetric Rails Thick Web Asymmetric Rail “Zu 1 -60” for switch points

Thick Web Asymmetric Rails Thick Web Asymmetric Rail “Zu 1 -60” for switch points Developed in-house and produced by SAIL

Envisaged End Forging of thick web rails Proposed Thick web asymmetric rail End forging

Envisaged End Forging of thick web rails Proposed Thick web asymmetric rail End forging facilities at BSP End use of TWR switches TWR End forged rail Std Rail

Thank You

Thank You

VOSSLOH FASTENINGS

VOSSLOH FASTENINGS

VOSSLOH FASTENING Sleeper screw in dowel Tension clamps Guide plate Rail Pad

VOSSLOH FASTENING Sleeper screw in dowel Tension clamps Guide plate Rail Pad