Global Unit Generation

From the 600/620°C to the 700/720°C-USC-PP History and Status Dr M. Bader

Global Unit Generation

The Motivation

Global Basic Conditions for the Energy Industry

Environmental Impact Climate protection and new technologies

Economics Competition in the European Market

Security of Supply Resources, mix of power

production and political framework

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 2

Global Unit Generation

The Road Of The Development

30%

35%

40%

45%

50%

55%

1950 1970 1990 2010 2030

Net

effi

cien

cy

Nickel Base Alloys (365 bar, 705°C)

Austenites (290 bar, 600°C)

Ferrites and Martensite (260 bar, 545°C)

Possible Step

Materials for SH and RH

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 3

Global Unit Generation

700/720°C Boiler (Demo- 500MW)

88m

Ni base alloys: - Material data - Design by analysis - Manufacturing - Welding

[Hitachi Power Europe GmbH Duisburg]

High pressure part Steam rating 334kg/s; 1024t/h Allowable operating pressure (gauge) 390 bar SH-Outlet temperature 705 °C Reheater Steam rating 285 kg/s Allowable operating pressure (gauge) 81 bar RH-Outlet temperature 720 °C

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 4

Global Unit Generation

R&D from 2007 - 2012

Steam generator

Piping

Turbine

NDT

Valve cast

Simulation

Housing cast

NDT

Material Characterisation

Rotor

Creep

Corrosion

improved UT

Weld HAZ

Membrane walls Concept of

Reparation

Super heater Bending

Welding

Forging pieces

Embrittlement

Main steam piping

HR - piping

Valves, Forgings Pieces

Cold Working

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 5

Global Unit Generation

700°C Boiler - Material Concept

13CrMo4.5

WB36

WB36 13CrMo4.5

Alloy 617m

10CrMo9.10 T91 S304

Inlet

Outlet

HR3C Alloy 617m

HR3C Alloy 617m

Alloy 617m

Alloy 617m

Alloy 617m

Alloy 617m

Alloy 617m Alloy 740

Alloy 617m

Alloy 263

Alloy 174

P92

Alloy 617m headers

13CrMo4.5 T24 T92 Alloy617m

[NRWPP700, Variant A]

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 6

Global Unit Generation

700°C Boiler - Material Concept

[NRWPP700, Variant B]

13CrMo4.5 T24 Alloy 617m

WB36

WB36 P91 Inlet

Outlet

P92

Alloy 617m

Alloy 617m

Alloy 617m

P91

P91

WB36

P91 headers

16Mo3 S304

HR3C Alloy 617m

Alloy 617m

S304 HR3C

HR3C Alloy 617m

P92

P92

Alloy 617m P92

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 7

Global Unit Generation

Damage SRC…?

Crack initiation In the welding area: 1. Shrinking stresses (σres)

2. In the HAZ (heat affected zone) 3. At the outer surface

(stresses caused by bending) Crack propagation Mainly in the base material: 1. Steered by the stress

(no different between HAZ and Parent Mat) 2. Intergranular crack (IC)

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 8

Global Unit Generation

Relaxation Cracking At A617-Welds

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 9

Global Unit Generation

R&D Road Regarding The SRC-Behaviour

Properties

Tensile tests: CSR 10-5/s CSR 10-6/s

Bending tests: 3 point bending 4 point bending

Characteristic value

microstructure

Optical microscope

TEM

Description of Influence

Alloy and Heat treatment

Simulation

980°C / 3h

Homogenizing

Solution annealing

Composition

Investigation Scope of variation

Time scale

SEM

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 10

Global Unit Generation

Welding: Influence of PWHT on Alloy617

• Welding = Casting = Shrinkage Stresses

• Heavy-walled a Stress Relief Annealing is necessary

• Normal Hardening of Nickel Base Alloy at 700°C (no plastic relaxation over

dislocation gliding) and stress induced gamma prime formation in HAZ

Operating area Stress relief annealing

VDM-Werkstoffdatenblatt Nr. 4119 (Januar 2005)

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 11

Global Unit Generation

Welding: Influence of PWHT on Alloy617 – Influence of Working Temp.

Working area

[Kirchhöfer, H. et al: Precipitation Behaviour of Hastealloy X and A617 (1984)] M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 12

Global Unit Generation

Status Of The Welding Technology For A617

Virgin material: As-delivered condition: solution annealed After welding: stress relief heat treatment (SRHT) 980°C/3h

For repair: Before welding:

Variant I: 980°C/3h (removal of γ’-phase) – necessary Variant II: 1160°C/1h (additional -removal of carbide-precipitations at grain boundaries ≅ reset the material structure in the initial status) – better weldability (however a challenging heat treatment)

After welding: stress relief heat treatment (SRHT) 980°C/3h

Remark: ongoing, tests of the repair methods in test rig “Enzio” and additional investigation programs

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 13

Global Unit Generation

Résumé

The classic process is technologically limited.

The main increase in efficiency is only possible with higher steam

temperature and afterwards with the steam pressure.

80% of R+D for the 700°C-PP is done.

No all solutions for the special technical questions are sophisticated.

History New technical levels brought also unexpected issues and failure.

M. Bader, From the 600/620°C to the 700/720°C-USC-PP (History and Status) 2013-03 14