attachment 09 - milan conference 2005

AD700AD700 AdvancedAdvanced 700°C PF Power Plant 700°C PF Power Plant

Advanced Materials forAD700 Steam Turbines

R.W. Vanstone (ALSTOM Power)

AD700 Turbine Group leader

AD700 – Advanced 700C PF Power PlantA Clean Coal European Technology

October 27th 2005, Milan


Steam turbine material development

Objectives

Identify suitable alloys

Demonstrate prototype manufacturing/welding

Define properties which determine allowable stresses

Investigate failure mechanisms


AD700-1

AD700-2

COMTES 700 Turbine Valve

Identification of 1st generationcandidate alloys

Screening tests

Selection of 2nd generationcandidate alloys

Prototype manufacture

Long term test programme

Turbine valve manufacture

Turbine valve operation

Turbine valve examination

Steam turbine materials:selection, demonstration and characterisation

October 2005

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009


Participants in steamturbine material

development

AD700-1 AD700-2 COMTES 700 Turbine Valve

Turbine makersAlstom PowerAnsaldo EnergiaSiemens

FoundriesDoncaster FVCGoodwin Steel CastingsHowmetSantasaloVoest-Alpine

ForgemastersAubert & DuvalBoehlerSaarschmiedeSdF TerniWyman Gordon

Research InstitutesAnsaldo RicercheCESICSMENEAJRCVGB

GeneratorsEDFElectrabelElsamEnergi E2EnBWEONPublic Power Corp ContractorRWEVattenfall Sub-contractor


Existing alloys in new applications

Alloys used for Aerospace andland based gas turbines

New operating regime (stress, temperature, environment)

New product forms(heavier, larger sections)


Materials requirements

Creep

Steam oxidationFlue gas corrosion

Minimum Cr content

Thermo-mechanicalcycling

2nd phase hardening: Ti, Al, Nb

Solid solution hardening:Mo, W, Co

Minimum cost: Fe

ManufactureWeldability

Economic feasibility

?

?

?


1st generation candidate materialsProduct form

AlloyStatic

castingCentrispun

casting Powdermet Forging155230263617625706

706M718

718M901

901Mwaspaloy


Screening tests on 1st generationcandidate materials

• tensile• creep• low cycle fatigue• toughness• as-received and long term aged conditions• evaluation of ultrasonic inspectability and

weldability


Kinetics of long term ageing in alloy 617

0

200

400

600

800

1000

0 500 1000 1500 2000 2500 3000 3500

Time at ageing temperature

Stre

ss (M

Pa)

Rp0.2 (650C ageing)Rp0.2 700C ageing)Rm (650C ageing)Rm 700C ageing)

0.0

10.0

20.0

30.0

40.0

50.0

0 1000 2000 3000 4000

Time at ageing temperatureSt

ress

(MPa

)

Cv (650C ageing)

Cv (700C ageing)


Forgings

Forgings: Minimum measured proof strength after ageing at 650 or 700°C

0

200

400

600

800

1000

1200

0 500 1000 1500 2000 2500 3000

Time (hours)

Stre

ss (M

Pa)

Forgings: Minimum measured proof strength

0

200

400

600

800

1000

1200

0 200 400 600 800

Temperature

Stre

ss (M

Pa)

718

706M

706

Waspaloy

901M

901

263

625

617

718: 13JWaspaloy: 25J

617: 10J

901M: 4J901: 8J

263: 13J625: 24J


Castings/PM

Castings and PM: Minimum measured proof strength

0

50

100

150

200

250

300

350

400

450

500

0 200 400 600 800

Temperature

Stre

ss (M

Pa)

625PM

263

625

155

230

617

Castings and PM: Minimum measured proof strength after ageing at 650 or 700°C

0

100

200

300

400

500

600

700

800

0 500 1000 1500 2000 2500 3000

Time (hours)

Stre

ss (M

Pa)

625PM: 24J

155: 8J

230: 13J

263: 13J

617: 18J625: 7J


Fracture toughness v impact strength

0

50

100

150

200

250

0 5 10 15 20 25 30 35

Impact strength (J)

Frac

ture

toug

hnes

s M

Pam

0.5

617

263

617

263


Castings LCF, 700C

0.10%

1.00%

10.00%

10 100 1000 10000

Cycles

Tota

l Str

ain

%


Welding trialsTHERMIE / Alloy C-263 / ASSESSMENT OF WELDABILITY

HARDNESS ACROSS THE WELD

100

150

200

250

300

350

400

450

-10 -5 0 5 10 15

DISTANCE (mm)

HA

RD

NES

S H

V2

ALLOY 263 CAST "G" /SAW

ALLOY 263 CAST "G"/ MMA

ALLOY 263 FORGED "KN" / SAWBASE METAL

WELD METAL

THERMIE / Alloy IN 617 / ASSESSMENT OF WELDABILITYHARDNESS ACROSS THE WELD

100

150

200

250

300

350

400

450

-10 -5 0 5 10 15

DISTANCE (mm)

HA

RD

NES

S H

V2IN617 FORGED "M" / SAWIN617 CENTRISP. "U" /SAWIN617 CENTRISP. "U" / MMA

BASE METAL

WELD METAL


Ultrasonic detectability

0

0.5

1

1.5

2

2.5

3

625PM(1) 625F(13) 718F(6) 718F(12) 718F(9) 263F(8) 263F(11) 617F(10) WASP(7) 901F(15)

DET

ECTA

BIL

ITY

LIM

IT (m

m)*

S1/trans.I

S2/long.

S3/trans.II

* Limit = mm FBH (flat bottom hole)

0

2

4

6

8

10

12

14

16

18

20

625C

(3)VIC

RO625(2

2

617C

(4)VIC

RO617(1

9

230C

(5)VIC

RO230(2

126

3C(16

)VIC

RO263(2

015

5C(14

)

DET

ECTA

BIL

ITY

LIM

IT (m

m)*

S1/trans.I

S3/trans.II

* Limit = mm FBH (flat bottom hole)

Forgings <2.5mm

Castings>10mm


• Solutions were identified for alloy and product formselection which met all the constraints of:– steam turbine design,– mechanical and physical property requirements,– and of component manufacture, fabrication and inspection.

• Forgings - 617, 625 (263, 718)• Castings - 617, 625• Bar products – waspaloy, 105

2nd generation candidate materials


Prototype rotor forgingsSaarschmiede:

•HP (700mm dia) forgings in617 and 625

•IP (1000mm) forging in 617

Boehler:

•IP (980mm) forging in 625

SdF Terni:

•HP (700mm dia) forging in718

Fortech

•HP (600mm dia) forging in263


• 617/625 : 10%Cr steel• TIG• Ni weld metal• PWHT defined by

10%Cr HAZ• Inspection by UT and

radiography

Rotor welding procedure


LIQUID WEIGHT = 6.035 kg ROUGH WEIGHT = 3.245 kg

625 valve chest cast byVoest-Alpine, April 2005


• As received condition:– tensile– fracture toughness– creep– fatigue crack growth– creep-crack initiation and growth– low cycle fatigue– creep-fatigue– steam oxidation

Prototype characterisation: parent• After 650C, 1000 hours:

– tensile– fracture toughness

– fatigue crack growth

– low cycle fatigue– creep-fatigue


– tensile cross-weld– fracture toughness HAZ WM– creep cross-weld– fatigue crack growth HAZ WM– creep-crack initiation and growth HAZ WM– low cycle fatigue cross-weld WM– creep-fatigue WM– steam oxidation WM

Prototype characterisation: weldments


• Alloys and product forms available• Near-net shape manufacturing v machining

from bar

• Wear resistance• Solid particle erosion resistance

Blading, bolt, valve components


• HP and IP rotor forging prototypes : manufactured and testprogramme in progress (>35,000 hours)

• Rotor weldments: procedure defined and demonstrated, long termtesting launched in 2005

• Model and prototype castings: manufactured and test programme inprogress (>35,000 hours): service operation in progress

• Casting weldments: manufactured and test programme in progress(15,000 hours)

• Blading: alloy/manufacturing procedure identified. SPE testingcomplete. Long term testing in progress (>10,000h).

• Bolting: alloys identified, relaxation testing in progress (>30,000h)• Valve components: wear testing complete: service operation in

progress

Component demonstration andcharacterisation: status October 2005


AD700-1

AD700-2

COMTES 700 Turbine Valve

Identification of 1st generationcandidate alloys

Screening tests

Selection of 2nd generationcandidate alloys

Prototype manufacture

Long term test programme

Turbine valve manufacture

Turbine valve operation

Turbine valve examination

Steam turbine materials:selection, demonstration and characterisation

October 2005

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009


• Alloys for 700-720C steam turbines identified• Prototype components manufactured• Comprehensive materials test programme in

progress

• Underpinning technology for mitigation ofcarbon emissions

• Facilitate transition to zero-emissiontechnologies

Conclusions


• Partners in AD700 and COMTES700 Turbine Valve projects

• AD700 funding bodies– European Commission– UK govt– Swiss govt

Acknowledgement

attachment 09 - milan conference 2005

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