Combustion Chamber Parts Piston Rings - FMV

Wear loaded components 

in large ship diesel engines 

Jesper Vejlø Carstensen 

MAN Diesel & Turbo Copenhagen 

Material Technology & Research 

MAN Diesel & Turbo 

FMV Temadag om slid / 2012-11-15 < 1 >

Outline 

• Short company presentation 

• Two-stroke diesel engine overview 

• Combustion chamber parts 

– piston rings 

– piston crown 

– exhaust valve spindle 

• Fuel pump parts 

– heavy fuel oil 

– bio fuel oil 

Company presentation Engine overview Combustion chamber parts Fuel pump parts 




Two-Stroke Head Office in Copenhagen 

Employees (2011-12-31) : 1,295 

Products 

Engine Components 

Spare Parts 

2-Stroke Engine 

Design 


Components 


Spare Parts 

PrimeServ 

Academy 

PrimeServ 

After Sales Service 




MAN Group 

Corporate Structure 

MAN SE 

Business 

area 

Commercial Vehicles 

Power Engineering 

Division 

MAN 

Truck & Bus 

Employees ‘11: 34,000 

MAN 

Latin America 


MAN 

Diesel & Turbo 


RENK 

(76%) 

Revenue ‘11: €9.0 bn 



Revenue ‘11: 

€0.4 bn 

The MAN Group in 2011: €16.5 billion revenue - 52,500 employees 





Areas of Activity 

• 2-stroke and 4-stroke engines for marine and 

stationary applications 

• Complete propulsion packages 

• Compressors and turbines for all industrial applications 

• Chemical reactors and apparatuses 

• Turnkey power plants 

• Operation and maintenance of power plants 

(MAN | PowerManagement) 

• After Sales Services like repair, spare part supply, 

retrofitting, recycling and monitoring of all MAN largebore 

engines and turbomachinery in use across the 

world (MAN│PrimeServ) 





Worldwide No. 1 Supplier of Two-stroke Diesel Engines 





Diesel Engine Programme from 450 kW to 87 MW 





Licensees Reported Order Books (Two-Stroke) 





Market Share (Two-Stroke) 

14% 

2% LOW SPEED ORDER BOOK 

ULTIMO JANUARY 2012 

MAN B&W 

Wärtsilä 

Mitsubishi 

84% 




Two-stroke Diesel Engine 

Overview 

Exhaust 

receiver 

Turbocharger 

Exhaust 

valve 

Combustion 

chamber 

Piston 

crown 

Scavenge 

ports 

12S90ME-C9: 

Dry mass: 2,070 t 

Height: 14.5 m – Length: 24.2 m 

Bore diameter: 0.9 m – Stroke: 3.3 m 

Water mist 

catcher 

Crosshead 

Connecting 

rod 

Bottom 

frame 

Piston 

rod 

A-frame 

Crankshaft 




Two-stroke Diesel Engine 

Combustion Chamber Parts 

Exhaust valve (spindle) 

Cylinder cover 

Fuel injection valve 

Piston (crown) 

Cylinder liner 





Piston Crown, Rings and Skirt 

Bore cooled 

piston crown 

Piston ring pack 

Piston skirt 





Piston Rings - Cast Iron 

surface after polishing 

surface after etching 

White phase = cementite 

Black phase = graphite 

Chatoyant phase = pearlite 

Light grey phase = ferrite 





Piston Rings - Cast Iron 

pearlite 

surface after polishing 

pearlite 

graphite 

cementite 

pearlite 

surface after etching 





Piston Rings and Cylinder Liner 

Cylinder liner Piston ring 

SO 3 

H 2 O 

Neutralisation 

Wetting/corrosion 

graphite 

pearlite 

cementite 

• Acid from gas phase dissolves in oil 

• Balance between neutralisation and 

adsorption ("wetting") of liner/ring 

• Amount of corrosion depends on: 

TBN, oil feed rate, neutralisation rate 





Lube Oil Dosage 

Minimum oil dosage to maintain 

hydrodynamic oil film 





Piston Ring Pack 

Hard Coat / Soft Coat Ring Package 

1st ring 

Vermicular cast iron base material 

Chrome-plated bottom face 

Cermet coating 0.5 mm 

Alu-coat for running-in 0.1 mm 

2nd ring 

Grey cast iron base material 

Chrome-plated bottom face 

Alu-coating 

3rd ring 


Alu-coating 


Cermet coating 0.3 mm 

Alu-coat for running-in 0.1 mm 

4th ring 





Plasma Spraying of Piston Ring Pack 

(W) 

(Cu) 

An inert gas is injected into an arc chamber 

framed by two concentric water-cooled electrodes 

(cathode and anode), ionizing the gas and 

creating temperatures up to 30,000°C. 

The gas expands and rushes from the torch as an 

ionized "plasma". A powder feedstock is injected 

into the plasma gas stream where it melts and is 

spray-cast upon the substrate surface. 





Plasma Sprayed Coatings on Piston Ring 

Alu-coat 

Cermet 

Base 

material 





Piston Crown 

Cross section of piston crown 

with piston rings (red) 

Piston ring grooves with 

hardchrome coating 

(hardness 900 HV) 





Piston Crown – Ring Groove Wear 

Worn off layer 

Demand for increased performance 

and compact design 

increased wear 





Particles in Worn Ring Groove 

exposed 

base material 

hardchrome 

50 µm 





Particles in Worn Ring Groove 

EDX mapping 

blue = Cr 

green = Al 

red = Si 

yellow = Al-Si 

EDX mapping 

blue = Fe 

green = Al 

red = Si 

yellow = Al-Si 





Cat-fines in Heavy Fuel Oil 

Diesel oil used for ship propulsion is so-called heavy fuel or bunker oil, which is the 

heaviest distillate from the refining of raw oil. The quality varies substantially. 

Catalyst particles are used to crack the oil. These are Al-Si rich particles with a 

large pore volume and large amounts of chemically bound water. 

Thermal and mechanical decomposition of catalyst particles 

Cat-fines 

M=Na + , K + 

D=Ca 2+ , Mg 2+ 

M x D y (Al x+2y Si n-x-2y O 2n ) · mH 2 O 




S e t t l i n g T a n k ( 2 5 ° C ) 

S e t t l i n g a n k 1 ( 6 0 ° C ) 

S e t t l i n g T a n k 2 ( 6 0 ° C ) T 


Fuel Oil System 

MDO 

MDO Storage Tank (25°C) 

HFO 

Centrifuge(s) 

(40°C) 

Service 

Tank 

(day) 

35°C 

Service 

Tank 

(day) 

90°C 

HFO Supply 

pump 

To Gensets 

HFO Circulating 

pump 

If unifuel system 

0,0 50,0 100,0 150,0 

Viscosity (cSt) 

Sep. efficiency (%) 

Separation efficiency vs. 

viscosity 

Bunker Storage Tank 1 (45°C) 



Centrifuge(s) 

(95 - 100°C) 

water 

discharge 

clean oil 

discharge 

solids 

discharge 

Temperature (dgr C) 

Separation efficiency 

100 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

40 50 60 70 80 90 100 

ldirty oil feed 

Separation efficiency vs. temperature 

l 





Ring Groove Wear Mechanisms 

Rotation of 

ring results in 

sliding wear 

Vertical movement of ring 

results in impact loads 

Ring 

Horizontal movement 

results in abrasive wear 

Oil 

Hard chrome 

Abrasive 





Ring Groove Wear – Preliminary Solution 

Hard chrome on 

piston ring underside 

Oil 

Ring 

Hard chrome 

Abrasive 

Hard chrome 

abrasive wear 

is minimized 





Ring Groove Wear – Long Term Solution 

Laser cladded cermet coating 

with coarse tungsten carbides. 

Carbide amount: 

60-75 vol% 

Carbide size: 45-160 µm 

Carbide hardness: 3-4000 HV 





Exhaust Valve – Spindle Guide 

Exhaust valve spindle guide – nitrocarburized grey cast iron 





Exhaust Valve – HVOF Coating on Spindle Stem 

HVOF coating consisting of Cr 3 C 2 in a matrix of NiCr 

as replacement for hard chrome 





Exhaust Valve – HVOF Coating on Spindle Stem 





Exhaust Valve – Spindle Disc 

Impact on valve seat area 

combined with high service 

temperature and corrosive 

environment 

Nimonic 80A 

Service temperature 

profile of spindle disc 





Exhaust Valve - DuraSpindle 

Austenitic 

stainless 

valve steel 

Rolling process, 

10 t load 

GMAW of 

Inconel 718 

Age hardening 

heat treatment 






Welding of DuraSpindle 

hardfacing (Inconel 718) 






1st groove 2nd groove 3rd groove 

Rolling depth 

Rolling of DuraSpindle 







720 o C / 8 hrs 

620 o C / 6 hrs 

24 hrs 

Hardening of DuraSpindle 


by 2-stage heat treatment 






Inconel 718 

Ni-Cr-W 

valve steel 

Potential cost saving is 100.000 DKK 

for a K98ME-C exhaust valve 

Seat hardness: 400 HV 

Seat hardness: 550-600 HV 

S60MC Nimonic spindle, 25.500 service hrs 

S60MC DuraSpindle, 33.900 service hrs 




Fuel Pump Parts 

Plunger and Barrel 

Barrel 

Plunger 





Plunger and Barrel 

Plasma nitrided 

Cr-Al alloyed steel 

Nitrided case: min. 0.4 mm 

Surface hardness: 900-1100 HV 





Plunger and Barrel - Scuffing 

Scuffing 

on plunger 

and barrel 





Plunger –PVD Coated 

C WC/C (a-C:H:W) 

BALINIT ® C, with its low coefficient of 

friction and good sliding properties, is 

deployed mainly to reduce adhesive wear 

(scuffing, seizing, cold-welding) and can 

also withstand high loads at deficient 

lubrication or dry running. 

New standard for 4-stroke 

Not (yet) implemented in 2-stroke 





Bio Fuel Applications 

Mouscron, December 2006 

17.6 MW Power plant 

18V48/60 4-Stroke engine 

Refined plant oil 





Bio Fuel Applications 

Wieze, September 2008 

35 MW Power plant 

2 x 18V48/60 4-Stroke engines 

Refined plam oil (stearine) 

1/3 goes to chocolate production 

while the rest is sold to the private 

supply network (60.000 households) 





Bio Fuel Properties 

Rape 

seed oil 

Palm oil 

Fish oil 

McDonald 

frying oil 

Tallow 

HFO 

(ref.) 

Density 

at 15 C 

Heat of 

combustion 

Viscosity 

at 100 C 

Kg/m 3 921 915 926 923 917 977 

MJ/kg 36,89 36,87 36,60 36,85 36,81 39,82 

cSt 7,88 8,33 7,23 11,30 7,41 32,27 

Carbon Mass% 77,7 76,6 77,5 77,2 77,4 86,8 

Nitrogen Mass% 1 < 0,1 0,1 < 0,05 < 0,05 0,4 

Sulfur Mass% < 0,05 0,007 < 0,05 < 0,1 < 0,05 0,93 

Total Acid 

Number 

(TAN) 

Mg KOH/g 2,4 11,0 13,1 3,9 40,5 < 1 





Refining Bio Fuels 

The distillative deacidification is a steam distillation 

The principal task of the steam treatment is to 

remove free fatty acids (reduce TAN to max. 4) 





Standard Plunger with Crude Palm Oil 

Fuel pump plunger 

(nitrided steel) after 

operation with crude 

palm oil for 1000 hrs. 

(TAN 12, un-refined) 





Standard Plunger with Crude Palm Oil 

Timewise progress 

1. Intercrystalline attack 

2. Grains fall out 

3. General corrosion 

Nitrided steel stored in crude palm oil 

for 500 hrs (top) and 2000 hrs (bottom) 





Standard Plunger with Tallow 

Fuel pump plunger (nitrided steel) after operation with tallow for 200 hrs (TAN 46, unrefined) 





Bio Fuel Tests on Fuel Pump Test Rig 

High 

pressure 

fuel to 

fuel valve 

Drain 

Fuel pump barrel 

Fuel pump housing 

Fuel pump plunger 

Fuel inlet 

Piston for 

puncture valve 

Puncture valve 

high pressure 

Fuel pump top cover 

Suction valve 

Lube hole 

Engine type: 90MC-C 

Fuel type: Crude palm oil 

Running hours: 200 hrs 

3 tests run with different 

sets of plunger and barrel: 

1. Nitrided steel (ref.) 

2. X90CrMoV18 

3. HS 6-5-2 

Steel C% Cr% W% Mo% V% 

High pressure fuel 

Low pressure fuel 

Atmospheric air 

Drain 

X90CrMoV18 0.9 18 - 1 0.1 

HS 6-5-2 0.9 4 6 5 2 





Two-Stroke Engine Operating on Bio Fuel 

Power plant site from PBB GmbH in Brake, Germany 

MAN B&W 7L35MC-S engine 

Engine: supplying 4.2 MW to the national grid and 3.6 MW to a palm-oil refinery situated nearby. 

Fuel: Crude palm oil with a Total Acid Number (TAN) of up to 15 mg/KOH/g. 






Larger fuel valves 

Introduced 

Larger fuel pumps 

introduced; 

modified materials 

Reinforced camshaft 

Introduced 






Cylinder liner Piston ring 

graphite 

pearlite 

cementite 




Thank you for your attention 



Disclaimer 

All data provided in this document is non-binding. 

This data serves informational purposes only and is especially 

not guaranteed in any way. Depending on the subsequent 

specific individual projects, the relevant data may be subject 

to changes and will be assessed and determined individually 

for each project. This will depend on the particular 

characteristics of each individual project, especially specific 

site and operational conditions.

Combustion Chamber Parts Piston Rings - FMV

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?