Different Types of Corrosion Extent of Rail Corrosion on IR Reasons for Extensive Rail Corrosion Various preventive measures adopted on IR &

efficacy of the same Trials of different preventive schemes -

Results / Inference Corrosion Resistant Rails Field Trials –

experiencei) Cu – Mo ii) Ni – Cu – Cr

Cost economics Suggestions / Recommendations.

Synopsis

Most metals are subjected to corrosion. This is due to the high energy content of the

elements in metallic form. In nature, most metals are found in chemical

combination with other elements. These metallic ores are refined by man and formed into metals and alloys. As the energy content of the metals and alloys is higher than that of their ores, chemical re-combination of the metals to form ore like compounds is a natural process.

Reverse Metallurgy ?

Driving Force for Corrosion

It is an electrochemical action which requires presence of water or solution.

Anode and Cathode are formed on same metal (Rail,liners,ERCs) having local difference either chemical or mechanical such as oxide, impurities,

Traces of water acts as electrolyte, hence a direct current thus flows attacking the anode as result of which deterioration of metal starts

Anode area -- Corrosion occursCathode area -- No Corrosion

Corrosion Mechanism

Atmospheric factors that cause rapid corrosion:a) high chloride content of the air in areas of coastal regionb) High sulphite – sulphate content of air, high

concentration of carbon particles as in industrialist areas. Uniform corrosion of rail leading to thinning of Rail foot &

web.

General corrosion occurs mainly in coastal areas due to continuous exposure of rails to saline atmosphere and humid environment. General corrosion affects both gauge face and non-gauge face side of web and foot.

Aggressive Saline environment= corrosion loss of metal in continuous rust layers which come out as flakes.

Types of Corrosion in Rails Atmospheric Corrosion

Fretting corrosion - attack accelerated by relative motionof contacting surfaces.

Fretting Corrosion

Due to dust particles/contaminants settled on the surface

Under certain specific conditions, particularly involving chlorides (especially in saline climate) and exacerbated by elevated temperatures, humid conditions - small pits form on surface of steel.

Dependent upon both the environment and type of steel small pits may continue to grow, and lead to perforation, while the majority of the steel surface may still be totally unaffected.

Pitting Corrosion

Rapid corrosion at crevices due to starvation of oxygen for the deep lying section, which becomes anode & surrounding area exposed to air acts as cathode. Crevices get filled with moisture that cannot evaporate & have small surface area

Crevice Corrosion

Localized corrosion occuring at the contact surface between the two metals due to small gap between the surfaces. Corrosion Pit on the top of Rail foot at Liner Contact area and weld collars mainly due to toilet droppings get entrapped between liner and foot of the Rail. Weld collars mainly SKV welds and partly flash butt welds also obstruct escaping toilet droppings giving rise corrosionpits corrosion pits only on the Gauge face of Rail.

Contd……

Extent of this corrosion – very severe, serious & alarming.

Corrosion 8mm or more at Rail foot (GF side)within 8 years (in coastal region as seen at BZA, VSKP

& MAS Divisions).

At some locations, even through holes at Rail foot at Liner contact.

Leads to rail fractures at Liner Contact area and weld failures at weld collar location.

Contd……Crevice Corrosion

Severe corrosion of Rail foot at LCA on GF side

Rail Renewal 2011-12 :- Condition Basis - 65%

Corrosion Account – 37%, Rail/Weld failures – 15%

Rail/Weld failures–predominant on account of rail corrosion

Corrosion predominant in coastal region, Station Yards, where passenger carrying trains large in number.

Corrosion very severe on the GF side on the top of rail foot at Liner contact area (Crevice corrosion), at SKV Weld Collars

Corrosion on non GF side on foot – insignificant

Corrosion on web & bottom of Rail Foot – relatively less except in major Station Yards.

Corrosion of Track Fittings – ERC & MS liner severe on GF side.

Corrosion at P&C in major Yards – severe on track fittings (Plate Screws, Stretcher bars, Lugs).

IR Scenario

Toilet droppings (Ammonia compounds) on top of Rail foot (GF side),

Saline climate (effect of chlorides) in coastal region,

Entrapment of moisture coupled with contaminants between Rail foot & Liner,

Ineffectiveness of preventive measures adopted,

Improper drainage in major yards,

Slackness/improper execution of the preventive schemes in vogue.

Reasons for Extensive Rail corrosion

Design Metallurgy - By alloying Prevention through chemistry

* Protective coating of Rails-Electroplating, Hot dip galvanising,

Metallising* Cathodic protection* Anticorrosive paints* Improvement in corrosive environment

Improvement to drainage, Artificial ventilation in tunnels etc

Corrosion Preventive Techniques

Corrosion Prevention – IRPWM Provisions

IRPWM Para No.250 (2) Anti-corrosive painting of Rails :- at locations prone for corrosion. For New Rails – before laying in the track. Scheme:- One coat of Zinc chromate/Red oxide primer to IS: 2074 Two coats Bituminous emulsion to IRS-P-30-1996 -350 microns thick (175 microns each) Inservice Rails:- Same Scheme Para No. 1411(5) : For E.R.Cs & M.C.I. inserts: Initial treatment – base depot – ERC & M.C.I. Inserts. Grease Graphite ‘O’

Rail Corrosion prevention – RDSO Guidelines

RDSO Lr. No. CT/IRPWM dt. 01.12.1999Painting of rails two pack epoxy paint for new & inservice rails in corrosion prone areas.

2. RDSO Lr No. CT/ACP dtd.22.10.2002:a) Painting mandatory during laying or after laying.b) Shifting of rail position.c) Interchanging of gauge faced) Grease graphite below liners.e) Shifting of outlets of toilets in the coaches from ends to centre.f) Galvanizing of rail foot as done on the OHE mast.

4. RDSO Lr No.CTE/ACP dtd.24.02.2006:a) New Rails - Zinc metalisation in severe corrosion prone areas.b) Inservice rails – anti-corrosive bituminous black to IS: 9862.

1) Bituminous emulsion to IRS-P-30-1996 as per IRPWM2) Four coats epoxy painting3) Two coats epoxy painting4) Rust-I-SOL and RUST SAFE (L&T Make)5) Inter seal 670HS (Surface total rate epoxy)6) Solvosol (Moisture cured Urethane)7) Red lead and Red oxide8) Anti Corrosive Bituminous Black to IS 98629)Sealing of liner contact area with Grease Graphite ‘O’10) Shifting of liner contact area along with destrssing11)Corrosion Resistant Alloy Rails

a) Co-Mo b) Ni-Cr-Cu12).Zinc metallisation

Anti corrosive Schemes tried on Vijayawada Dvn.

Red Lead + Red Oxide Painting Scheme

Painting of New Rails on the Cess. details of scheme

i. 1st coat (primer coat): Red lead paint by mixing 3.3 kg dry pigment Red lead powder to IS Type C 57-1989 with 1 lt. linseed oil (boiled) to IS 77/1966 to thickness of 80 microns.

ii. 2nd coat: Red oxide (1st finishing coat): Ready mixed Red oxide to IS 123-1962 to thickness of 45 microns mixed with lamp black (to distinguish from the final coat).

Painting system for new rails

Contd…..

iii. 3rd coat (2nd finishing coat): Ready mixed Red oxide paint to IS 123-1962 to thickness of 45 microns.

Drying period of Red Lead 48 hrs. hence not feasible for painting In-service Rails.

This system found to give reasonable protection to Rails for 2-3 years after which it becomes due for In-service maintenance painting.

Painting system for new rails

Contd……

Painting of In-service Rails mainly for preventing general corrosion.

1st coat: Anti corrosive bituminous black paint to IS 9862-1981 to thickness of 100 microns.

2nd coat: Anti corrosive bituminous black paint to IS 9862-1981 to thickness of 100 microns.

In service painting should be done depending upon Rail condition, but not earlier than 2 years.

Painting system for In-service Rails Anti-corrosive Bituminous Black to IS 9862

Prevention of Pit Corrosion.

The above painting systems- effective in preventing general corrosion but not so in arresting Pit corrosion at Lliner Contact area, as the painting layer gets mainly disturbed due to abrasion and impact while driving of Liner and ERC.

Sealing of liner contact area with Grease Graphite’O’ adopted to overcome this successfully.

Method of carrying out sealing of liner contact area

To prevent the ingress of moisture, contaminants, toilet dropping, Grease Graphite `O` to IS 408-Applied all around the Liner on Rail foot only on Gauge face side of Rail.

Any corrosion pits found near and around Liner contact area and weld collar to be filled up with Grease Graphite. Grease applied on both the sides of MCI insert on the Gauge face side which forms a sealant and prevents ingress of toilet water/moisture into the MCI insert which prevents seizure of ERCs - a major maintenance hazard.

Unprotected Rail after 5 years service i.e. No painting or sealing (LCA shifted)

Newly sealed liner contact area after in service rail painting

Sealed liner contact area after one year

Description Unit Consum-ption per unit per year(Kg)

Total requirement for the year (Kg) BZA

Sealing of LCA with Grease(110 Kg. Per unit once in a year)

T.Km 110 180864

Curve Greasing (14.5 Kgs. Per unit once in 3 weeks)

T.Km 250 84121

SEJ Greasing (1 Kg per set once in a month)

Set 12 11952

Quantity Assessment for Grease

Description UnitConsum-ptionper unit per year(Kg)

Total requirement for the year(Kg) BZA

P&Xings Greasing (1.5 Kgs per set once in 15 days)

Set 36 65653

Steel fittings of Channel Sleepers (0.2 Kg per sleeper once in 6 months)

Per Sleeper

0.4 11558

Total 354148

Quantity Assessment for Grease

Sealing of liner contact area with Grease Graphite ‘O’ - efficacy

Adequate quantity of Grease to be planned & procured Requirement about 110 Kg/Tkm for carrying out sealing once in a year During recent visit to Vijayawada Division, need for further upward revision of the requirement to 150 Kg/Tkm felt.Cost of Grease (Year 2010) : Rs.90/Kg (incl. of Taxes) Cost of Sealing of liner contact area with Grease Rs. 16000/Tkm/year (110 Kg/Tkm) Rs. 19000/Tkm/year (150 Kg/Tkm)

Contd…..

Prior to adoption of this scheme, corrosion at Liner Contact area of Rail Foot – of the order of 0.8 mm –1mm/year on BZA Division. Subsequent to adoption of the scheme, Crevice Corrosion is 0.2 mm–0.3mm /year as observed & assessed during Feb. 2011. Reduction in Crevice Corrosion of Rail foot at Liner contact by 70%-75% which is substantial. Observed to be most effective ,of all the corrosion preventive schemes adopted. Incidentally, this scheme developed at VijayawadaDivn. was adjudged as one of the three best Innovations on IR by Railway Board during 2005-06.

Sealing of Liner Contact area with Grease Graphite ‘O’ - Efficacy

Contd…..

Protected Rail after 6 years i.e. painted and sealed.

Sealing with grease also very effective on Plate screws at Points and SEJs. The plate screw head will be protected against corrosion and seizure of screws can also be prevented simultaneously.

Plate screws before sealing

Plate screw after sealing

Filling of corrosion pit with grease at SKV weld collars (Pit formed already).

Protection of weld collar with grease coating over bituminous black paint

(No corrosion pit)

Anti-corrosive treatment of Rails, Welds and other P.Way Fittings (ESO No. 59 dt. 02.01.2008)

(A) Frequency of lubrication of ERCs and sealing for liner contact area:i. Corrosion prone locations : ERC greasing (all 4 ERCs) and sealing of inside liner contact area– Once in a yearii. Other locations: ERC greasing (all 4 ERCs) – Once in 2 years

(B) In addition, on identified corrosion prone areas painting of new rails and in service rails :i) Painting of new rails: Before laying: one prime coat of Red lead and two coats of Red oxide. ii) Painting of in-service rails: Depending upon condition, but not earlier than once in two years on inner gauge face (web and flange) using two coats for anti-corrosive Bituminous black paint to IS-9862 – 1981.

Rail Corrosion Prevention – SCR instructions

Contd…..

(C) Weld collar painting:Identified corrosion prone areas - once a year, with two coats of anti-corrosive bituminous black paint (thickness 200 microns) to IS-9862 1981 Non-corrosive prone areas- once in two years.

(D) Use of galvanized metal liners, galvanized plate screws and stretcher bars in points and crossing areas.i) Galvanized liners – In all identified corrosion prone areas . ii) Galvanized Plate screws and Stretcher bars - In all areas irrespective of corrosion Proneness.

(E) Lubrication of Plate screws at P&Csi) Corrsion Prone areas – once a year. ii) In other areas – once in two years

(F) Corrosion prone Sections - identified in each Division.

Contd…..

Corrosion on Rail foot due to Liner Bite - Protection (shifting of Liner Contact area along with destressing)-SCR-ESO dt. 28.01.2009

o To overcome problems of Rail failures, arising out of deep corrosion pits under the Liner seat –Destressing involving shifting of Liner Contact area irrespective of any other criteria. Minimum shift of liner contact area 150mm by pulling rail in the direction of Traffic on Double Line.

At an interval of 5 years, or, before corrosion pit depth at liner contact area reaches a limit of 1.5mm, which ever is earlier.

Contd…..

Next round of destressing after 5 years or before corrosion pit depth at liner contact area reaches 1.5mm at shifted locations, whichever is earlier.

Above operation repeated till Rail reaches full GMTor no possibility of further shifting of Rail due to existence of a number of pits.

In non-corrosive areas, no time limit of 5 years.o Inservice painting of Rails – Web & Top Flange only on GF

side at other than platform lines.At platform lines in Yards Non GF side also to be painted.

Contd…..

Shifting of LCA during destressing

LCA Shifted

Galvanized Metal liners on Gauge side of rail (LCA Shifted).

Sand blasting/flame cleaning - Expensivepower/hand wire brushing – practical, economical & serve the purpose for rail surface.

Power wire brushing designed & tried on BZA Division of SCR & found to be practical in execution at field.

Portable Generator, de-rusting kit consisting of rotating wire brush, hand held power handle

Cost: Rs.40000/Tkm (rail web & bottom flange)

Mechanised Surface Preparation of Rail

Tools & Equipment for Mechanised Cleaning of Rail surface

Mechanised cleaning of Rail surface with Roller Brush

Rail surface after Mechanised Cleaning

Nearly half the zinc of commerce – used for metal coating/galvanising

Zinc coating-by hot dipping, electrolysis, spraying, vapour deposition, cementation

Zinc metallisation by spraying technique for new rails just commenced at FBWP/Moulali of SCR. Approximate cost Rs.8 lakhs/Tkm ( Web & Top of Flange, both sides), Zn coating - 150 micronsEtch wash, Zn cr- 45microns Al paint- 70 microns

Spraying by oxy-acetylene spray gun/plasma gun Globules of molten metal flatten out against the surface

& flow into pores/irregularities which lock the coating. existence of pores in coating not damaging since zinc is

anodic to Iron & tends to protect it.

Zinc Metallisation

Development of Corrosion Resistant Rail Steel undertaken as Academia – Industry – User CollabarativeResearch Programme under aegis of Technology mission for Railway Safety (TMRS)IIT/Kanpur-SAIL-IR Significance of Crevice Corrosion at Liner Contact area of Rail Foot with special reference to discharge from Coach toilets Composition of Normal 90 UTS Rail (C-Mn Rail)

C-0.71% Mn-1.04% (wear resistant grade) Micro Alloying with low amounts of elements to induce passivity in iron Alloying elements : Ni, Cu, Cr & Mo in low amounts –effective where surface gets dried easily by sunlight, after periodic wetting due to rain or dew.

Corrosion Resistant Rail

Corrosion resistant Cu-Mo Alloy rails

C - 0.69% Cu – 0.24% Mo – 0.18%

Subjected to field trials on Vishakapatnam & Vijayawada Divisions (laid in the year 2004) Showed improved performance vis-à-vis normal 90 UTS Rail due to formation of protective magnetite on Cu-Mo Rails Cost about 30% higher than normal 90 UTS Rail due to import of Mo

IR entrusted for development of new alloy Rail Steel to IIT/K

Corrosion resistant Ni-Cu-Cr (NCC) Rail Lab results : NCC Steel showed best performance

w.r.t. (a) Alternate drying & wetting(b) Fretting Resistance Crevice corrosion studies in Lab:

Flat rectangular piece 50x50x10 mm from rail foot with 10mm hole at centre immersed in solution 3.5% NaCl + 3.5% FeCl3 at

ambient Temp. for 30 days. Later surfaces characterised for extent of localised

corrosion by SEMDepth of corrosion attack at crevices by optical laser

surface profilometer. Rougher the surface – indicates higher degree of

corrosionNCC Rail steel – showed least roughness Contd….

Arrangement for conducting crevice corrosion test for NCC Rails

Results from Profilometer Analysis at Crevice Locations on immersion in 3.5% NaCl + 3.5% FeCl3

for 30 days

General Corrosion studies in Lab Rails with entire assembly exposed to cyclic fog chamber for 6 months & subjected to alternate salt fog exposure for 2 hours and drying for 22 hours in a day.

Outer loose rust & inner adherent rust collected separately from foot of rail and subjected to characterisation techniques (spectroscopy, SEM etc.

enchanced corrosion protection of NCC Rail co-related to higher amount of Magnetite and Goethite in the rust

Corrosion resistant Ni-Cu-Cr (NCC) Rail

MACRO IMAGES OF the foot portion of rail steel: (a) C-Mn, (b) Cu-Mo and (c) Cr-Cu-Ni showing microscopic features (observed by SEM) of the outer rust on the rail steels; (d, e & f) after six months of salt fog exposure showing the lower rusting and compact rust formation in the case of Cr-Cu-Ni rail steel.

Surface condition of C-Mn, Cu-Mo and NCC rail pieces after six months of salt fog exposure showing the lower rusting in the case

of NCC rail steel.

Cu-Mo Railsa) laid on BZA-VSKP Section (3.5 km on one side only) during April 2004 & GDR-BZA Section in March 2006.b) Normal 90 UTS Rails & ACR Rails laid in pairs for comparison.c) Corrosion at LCA & at other locations on surface of Rail lower by 40%-60% than normal 90 UTS Rail (Sealing of LCA done since laying once a year.d) But Pit Corrosion at LCA more than Normal 90 UTS Rail, where Sealing of LCA done only after 4 yrs. of laying for Cu-Mo Rail,while for Normal RailSealing done once a year since laying.d) Costlier by about 30% than normal 90 UTS Rails.

Corrosion Resistant Rails – results offield trials on BZA Division

Item Cu-Mo Rails Normal 90 UTS Rails

GFmm

NGFmm

GFmm

NGFmm

Corrosion pit LCA

0.6-0.7 0.08-0.1 1.0-1.3

0.08-0.1

Loss of flange width

0.15-0.25 0.04-0.05 0.6-0.8

0.1-0.3

Remarks Rails not painted &Sealing of LCA done since laying

Rails paintedSealing of LCA done since laying

Cu-Mo Rails – Corrosion Measurement Feb. 2011Div. : BZA Section: GDR-BZA SVPM-KVZ

Rail : 52 Kg. 3.1Km GMT : 34 Laid : Mar. 2006

Cu-Mo Rails – Corrosion Measurement Feb. 2011Div. : BZA Section: GDR-BZA SPF-BPP

Rail : 52 Kg. 3.0Km GMT : 34 Laid : Feb.2006

Item Cu-Mo Rails Normal 90 UTS Rails

GFmm

NGFmm

GFmm

NGFmm

Corrosion pit LCA

1.0-2.6 - 0.2-1.2 -

Remarks Rails not painted &Sealing of LCA done after 4 years

Rails paintedSealing of LCA done since laying

a) Laid on GDR-BZA Section of SCR in Feb. 2009 (3.1 Km)b) Normal 90 UTS Rails & NCC Rails laid in pairc) Corrosion at liner contact after 2 years (Feb.2011) -i) NCC Rail-100 microns.ii)Normal 90UTS Rails200 micronsat Stn. Approach. No Corrosion on both at other locations.d) General Corrosion at other than LCA insignificant. e) Needs to be observed & corrosion to be monitored duly recording the readings on half yearly basis for at least another 3 years before taking final decision for adoption or otherwise.f) Cost: i) NCC Rail : Rs.71,000/MT (Rs.85 lakh/Tkm – 60 Kg Rail)Normal 90 UTS Rail: Rs.57000/MT (Rs.68 lakh/Tkm – 60

Kg)ii) NCC Rail costlier by 25% than normal 90 UTS Rail.

Ni-Cu-Cr Rails

Normal 90 UTS Rail (60 Kg)Corrosion Pit 200 microns(Stn approach) – After 2 yrs

NCC Rail (60 Kg)Corrosion Pit 100 microns(Stn. approach) – After 2 yrs

Normal 90 UTS Rail (60 Kg) NCC RailNo Corrosion Pit (mid section)

Glass Fibre Reinforcement as Strengthening/Preventive measure

S.Rly developed system of strengthening corroded Rail foot with Glass Fibrereinforcement glued at LCA

Lab results – enhanced load carrying capacity of locally strengthened corroded rail

Trials for provision of GFR at top of rail foot for entire length as preventive measure

Practical aspects of execution, performance, efficacy & cost economics under study

Scheme

Scheme details

Cost/Tkm(Rs. in lakhs)

Performance

Remarks

1) Red lead & Red oxide

New Rails on CessThickness: 170 microns(80+90)

1.25 Effective for 3-4 years

Surface preparation by mechanisedmeans practically adoptable developed on Vijayawada Dvn.& just put in practice.

2) Zinc chromate, zinc chromate red oxide & red oxide.

New Rails on cessThickness: 170 microns (45+35+90)

1.40 To be tried & studied.

Since red lead is likely to be banned from environmental consideration, this

scheme found to be effective in case of steel girders can be

tried.

Anti-corrosive Schemes adopted for rails & efficacy

Contd….

Scheme Scheme details

Cost/Tkm(Rs. in lakhs)

Performance Remarks

3) A.C bituminous Black IS9862

Inservice rails (two coats)Thickness: 200 microns

0.25 (GF)

Effective for 2 years

- do -Frequency: once in 2 Yrs.

4) Sealing of LCA with grease graphite ‘O’

Grease all around the liner sealing the gap between liner and rail foot on GF side.Central leg of ERC & the hole of MCI insert

0.20 Quite effective in prevention of ingress of moisture & contaminants at the liner contact area.

Rate of corrosion is hardly 0.1 to 0.2mm/year as against earlier 0.8-1.0mm/year on GF side in coastal region.

Anti-corrosive Schemes adopted for rails & efficacy

Contd….

Contd….

Scheme

Scheme details

Cost/ TkmRs.

Performance Remarks

5) Zinc metallisation

New rails at centralisedlocation (FBWP/Steel Plant)

8.0 lakh

To be tried & studied

Zinc Metallisation just commenced at FBWP/ Moulali/SCR. Efficacy & Economics in terms of life cycle cost to be studied (could be effective for 5-6 years)

6) Shift of LCA,withdestressing

As per ESO:60 28.1.09 of SCR

0.20 lakh

Effective. Further, adequate data will be available in next 3-5 years.

a) Creating of gap of 150-200 mm

b) pulling rail with rail tensor using hydraulic pump of weld trimmer 0.50-0.75 km at a time.

c) Thereafter destressing

Contd….Anti-corrosive Schemes adopted for rails & efficacy

Contd….

Scheme Scheme details

Cost/Tkm(Rs)

Performance Remarks

7) Corrosion resistant rails (Cu-Mo)

Cu-Mo rails & normal 90 UTS rails laid in pair

Corrosion at liner seat lower compared to ordinary 90 UTS (C-Mn rail)

Costlier by 30% than normal 90 UTS rails

8) Corrosion resistant rails Ni-Cu-Cr

Ni-Cu-Cr Rails & Ordinary 90 UTS Rails laid in pair

76 Lakh- 52 kg.costlier -15.5 Lakh.

80 Lakhfor 60 kgcostlier -18Lakh

Corrosion lower than normal 90UTS . To be observed for at least another 3 yrs. before taking final decision for adoption or otherwise.costlier 25% than normal 90 UTS

a) Lab test results promising & better than Cu-Mo rails.

b) 5% cheaper than Cu-Mo

c) rate of corrosion to reduce with passage of time.

Anti-corrosive Schemes adopted for rails & efficacy

Effective / promising Rail Corrosion Preventive Measures

Painting of New Rails before laying in track:- (Red lead & Red oxide scheme)(except top, sides & bottom of Rail Head)

To Conclude

Contd……

Alternative scheme for New Rails (since red lead is banned/likely to be banned, Zinc Chromate and Red Oxide Scheme)

i) Primer coat : a) ready mixed Zinc chromate to IS 104 one coat – thickness 45 microns (Yellow)

b) Zinc chromate red oxide to IS 2074 one coat - 35 microns

ii) Finish Coat : Red oxide ready mixed – two coats (each 45 microns thick – 90 microns) to IS 123-1962

Painting of Inservice Rails : Anti-corrosive bituminous black to IS 9862-1982 in 2 coats each 100 microns (frequency as specified in ESO 59 of SCR)Detailed procedure order for Red lead + Red oxide scheme for New Rails, Anti-Corrosive Bituminous Black painting scheme for In-service Rails as issued by SCR in 2004.

Mechanised surface preparation of New rails (method as found satisfactory during trials in the last three years on Vijayawada Division) before application of paint

Contd……

Contd……

Sealing of liner contact area of rail on GF side with grease graphite ‘O’Procurement of adequate quantity of Grease Graphite (about 150 Kg./Tkm) exclusively.

Shifting of liner contact area along with destressingperiodically as detailed in ESO 60 dt.28.01.09 of SCR.

Galvanisation of track fittings Viz., MS liners, plate screws, stretcher bars and lugs.

Use of corrosion resistant Ni-Cr-Cu rails – if trials prove to be effective and economical based on life cycle cost (these rails costlier by Rs.14100/MT Viz., 25% as per the prevailing price in the year 2010).

Contd……

Contd……

Effective / promising Rail Corrosion Preventive Measures

Interchange of rails – to be done selectively since flash but welds are aligned on one face only (GF), as it can result in alignment defects and hence, rough ride.

Epoxy painting schemes – totally failed since it requires highest quality surface preparation, otherwise paint peels off in flakes within a few months.

Change in position of toilet chutes of coaches to the centre of track instead of rail foot location/ Zero discharge toilets

Contd……Effective / promising Rail Corrosion

Preventive Measures

Zinc metalisation of Rail Foot & Web for new rails at centralised locations (at FBWP of Zonal Railways) –work just commenced on trial basis at FBWP/Moulali of SCR – if field trails prove to be satisfactory and economical in terms of life cycle cost (cost about Rs.8 lakh/Tkm)

Cold galvanising of rail foot & web for new rails at centralised locations (at FBWP of Zonal Railways ) –Trials can be undertaken.

Impregnated MS liners to prevent ingress of moisture and contaminates, toilet droppings etc. between liner and rail foot. Trial just commenced on VijayawadaDivision appears to be promising to be closely monitored and watched for its efficacy to prevent pit corrosion of rail foot at liner contact area.

Contd……