The failure analysis of 9–12% chromium steel tubes, containing about 2.5% molybdenum, is discussed in the present study. The component is used in a steam power plant boiler as a high-temperature superheater tube and has been in service for about 100,000 h. The failure occurred without appreciable wall thinning. Specimens were taken from the region beneath the fracture surface and investigated by optical and electron microscopes. The microstructure was composed of ferrite and grain boundary particulate carbides. The results indicated that the fracture was initiated because of the bending of the tube near the anchor and propagation of the crack through the interfaces between massive carbides and matrix (sensitized zone). Final fracture has occurred as a result of an overload due to the decreasing of load carrying section produced by crack propagation.

Issue Section:
Materials and Fabrication
Keywords:
alloy steel, chromium alloys, electron microscopy, failure analysis, fracture, heat exchangers, molybdenum alloys, optical microscopy, pipes, surface cracks, superheater, sensitization, buckling, steam power boiler
Topics:
Buckling, Failure analysis, Fracture (Materials), Fracture (Process), Steam, Steel, Stress, Superheaters, Temperature, Pressure, Failure, Grain boundaries, Thermal stresses, Boilers
1.
Khare
,
A. K.
, 1981, “
Ferritic Steels for High Temperature Applications
,”
ASM International Conference
, Warrendale, PA.
2.
Pugh
,
S. F.
, and
Little
,
E. A.
, 1978,
Proceedings of the BNES International Conference on Ferritic Steels for Fast Reactor Steam Generators
,
BNES
,
London
.
3.
Orr
,
J.
, and
Di Gianfrancesco
,
A.
, 1992, “
The Effect of Compositional Variations on the Properties of Steel 91
,” VDEh ECSC Information Day, The Manufacture and Properties of Steel 91 for the Power Plant and Process Industries, Dusseldorf, Nov. 5, Paper No. 2.4.
4.
Mann
,
S. D.
, and
Muddle
,
B. C.
, 1993,
Proceedings of the Microstructure and Mechanical Properties of Ageing Material
,
TMS
,
Warrendale, PA
.
5.
1998,
ASM Handbook, Failure Analysis and Prevention
, Vol.
11
,
ASM International
,
Materials Park, OH
, pp.
602
–
627
.
6.
TABRIZ Thermal Power Plant, Alesthom Atlantique, TB1-10.
7.
Shigley
,
J. E.
, 1986,
Mechanical Engineering Design
, 1st metric ed.,
McGraw-Hill
,
New York
, pp.
67
–
68
.
8.
Allen
,
H. G.
, and
Bulson
,
P. S.
, 1980,
Background to Buckling
,
McGraw-Hill
,
New York
, p.
92
.
9.
Singh
,
S.
, 2005,
Theory of Elasticity
, 4th ed.,
Khanna
,
India
, pp.
656
–
660
.
10.
Port
,
R. D.
, and
Herro
,
H. M.
, 1991, “
Corrosion-Fatigue Cracking
,”
The Nalco Guide to Boiler Failure Analysis
,
McGraw-Hill
,
New York
, pp.
169
–
180
and
244
–
245
.
11.
Port
,
R. D.
, and
Herro
,
H. M.
, 1993, “
Corrosion-Fatigue
,”
The Nalco Guide to Cooling-Water System Failure Analysis
,
McGraw-Hill
,
New York
, pp.
227
–
238
.
12.
Lancha
,
A. M.
,
Lapena
,
J.
,
Serrano
,
M.
, and
Gorrochategui
,
I.
, 2000, “
Metallurgical Failure Analysis of a BWR Recirculation Pump Shaft
,”
Eng. Failure Anal.
1350-6307,
7
, pp.
333
–
346
.
Crossref
Search ADS
 
13.
1975,
Metals Handbook, Materials Characterization
, Vol.
10
,
ASM International
,
Materials Park, OH
, pp.
95
–
125
and
533
.
14.
Jahromi
,
S. A.J.
,
AliPour
,
M. M.
, and
Beirami
,
A.
, 2003, “
Failure Analysis of 101°C Ammonia Plant Heat Exchanger
,”
Eng. Failure Anal.
1350-6307,
10
, pp.
405
–
421
.
Crossref
Search ADS
 
15.
Bose
,
S. C.
,
Reddy
,
S. V.
, and
Singh
,
K.
, 2000, “
Interdependence of On-Load Corrosion, Creep-Rupture and Copper Deposit in Augmenting Failure Processes of Boiler Tubes
,”
Corrosion
,
56
(
11
), pp.
1158
–
1169
.
Crossref
Search ADS
 
16.
Furtado
,
H. C.
, and
Le May
,
I.
, 2002, “
Evaluation of a Usual Superheated Steam Pipe Failure
,”
Mater. Charact.
1044-5803,
49
, pp.
431
–
436
.
Crossref
Search ADS
 
Copyright © 2009
 by American Society of Mechanical Engineers
You do not currently have access to this content.