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ASTM Selected Technical Papers
Quantitative Methods in Fractography
By
BM Strauss
BM Strauss
1
Teledyne Engineering Services
,
Waltham, MA 02254-9195
;
symposium cochairman and editor
.
Search for other works by this author on:
SK Putatunda
SK Putatunda
2
Wayne State University
,
Detroit, MI 48202
;
symposium cochairman and editor
.
Search for other works by this author on:
ISBN-10:
0-8031-1387-0
ISBN:
978-0-8031-1387-9
No. of Pages:
176
Publisher:
ASTM International
Publication date:
1990

A technique is described for establishing the microstructural features associated with the initiation of brittle fracture in weld metal and heat-affected zone (HAZ) crack-tip opening displacement (CTOD) test specimens. The technique involves detailed optical and scanning electron microscope examination of fractographic features to establish the local directions of fracture propagation at various locations on the fracture surface. This information is used to trace fracture propagation back to the region of initiation. In many instances, the precise initiating feature can be located and identified. Once identified, the fracture initiation position is marked and the specimen sectioned through this point to allow the region in which fracture initiated to be examined metallographically and related to the surrounding microstructure. Details of the technique are discussed.

Examination of steel weld metal and HAZ regions has revealed nonmetallic inclusions, pearlite colonies, second-phase regions (martensite, retained austenite, or carbide), and localized regions of intergranular fracture as the initiating features. The significance of these findings is considered with regard both to the size of features at which cleavage fracture initiates and to scatter in CTOD values.

1.
Harrison
,
J. D.
, “
The State-of-the-Art in Crack-Tip Opening Displacement (CTOD) Testing and Analysis
,”
Metal Construction
, Vol.
12
, No.
9
,
1980
, pp. 415–418 and 420–422.
2.
Sparkes
,
D. J.
, “
The HAZ Microstructure and Toughness of 3 kJ/mm Multipass Welds in Microalloyed C-Mn Steel
,” Research Report 380/1988,
The Welding Institute
, Cambridge, England,
09
1988
.
3.
Pisarski
,
H. G.
and
Pargeter
,
R. J.
, “
Fracture Toughness of Weld Heat-Affected Zones (HAZs) in Steels Used in Constructing Offshore Platforms
,”
Proceedings
, Conference on Welding in Energy-Related Projects,
Toronto, Canada
,
09
1983
,
The Welding Institute of Canada, Pergamon Press
,
Willodale, Canada
, pp. 415–428.
4.
Harrison
,
P. L.
and
Hart
,
P. H. M.
, “
HAZ Toughness of Thick Section Structural Steel
,”
Proceedings
, Conference on Weld Failures, Paper 45,
The Welding Institute
,
London
,
11
1988
.
5.
Ikawa
,
H.
,
Oshige
,
H.
, and
Tanoue
,
T.
, “
Effect of Martensite-Austenite Constituent on HAZ Toughness of a High-Strength Steel
,”
Transactions of the Japanese Welding Society
, Vol.
11
, No.
2
,
1980
, pp. 3–12.
6.
Nakanishi
,
M.
,
Komizo
,
Y.
, and
Fukada
,
Y.
, “
Study on the Critical CTOD Properties in the Heat-Affected Zone of C-Mn Microalloyed Steel
,”
The Sumitomo Search
, Vol.
33
, No.
11
,
1986
, pp. 22–34.
7.
Haze
,
T.
and
Aihara
,
S.
, “
Metallurgical Factors Controlling HAZ Toughness in HT50 Steels
,” IIW Doc. IX-1423-86,
International Institute of Welding
,
Tokyo
,
1986
.
8.
Baryshev
,
V. M.
,
Shebaron
,
A.
,
Birbrover
,
A. M.
, and
Malov
,
V. V.
, “
Increasing the Cold Resistance of Weld Metal in the Multipass Submerged-Arc Welding of a Low-Alloy Steel of Type 16ZAF
,”
Welding Production
, Vol.
25
, No.
7
,
1978
, pp. 43–45.
9.
Tweed
,
J. H.
and
Knott
,
J. F.
, “
Microstructure-Toughness Relationships in a C-Mn Weld Metal
,”
Proceedings
, Fourth European Conference on Fracture (ECF-4),
Maurer
K. L.
and
Matzer
F. E.
, Eds.,
Materials Advisory Services Ltd.
,
Warley, England
,
1982
, pp. 127–133.
10.
Pisarski
,
H. G.
,
Harrison
,
P. L.
, and
Naylor
,
K. D.
, “
Influence of Post-Weld Heat Treatment on the HAZ Fracture Toughness of Two Structural Grade Carbon-Manganese Steels
,”
Proceedings
, Vol.
III
, Seventh International Offshore Mechanics and Arctic Engineering Symposium,
Houston, TX
,
1988
,
The American Society of Mechanical Engineers
,
New York, NY
,
1988
, pp. 199–206.
11.
Harrison
,
P. L.
, “
Factors Influencing the Toughness of Molybdenum-Bearing Cellulosic Weld Metals
,”
Proceedings
, Conference on Welding and Performance of Pipelines,
The Welding Institute
,
London
,
1986
, pp. 23–27.
12.
Abson
,
D. J.
, “
The Influence of Manganese and Coating Basicity on the Microstructure and Mechanical Properties of Vertical-Up MMA Welds in 38-mm-thick C-Mn-Nb Steel Plate-Final Report
,” Research Report 309/1986,
The Welding Institute
, Cambridge, England,
08
1986
.
13.
Ito
,
Y.
and
Nakanishi
,
M.
, “
Study on Charpy Impact Properties of Weld Metal with Submerged-Arc Welding
,”
The Sumitomo Search
, Vol.
15
, No.
5
,
1976
, pp. 42–62.
14.
Terashima
,
H.
and
Hart
,
P. H. M.
, “
Effect of Aluminium on C-Mn Steel Submerged-Arc Weld Metal Properties
,”
Welding Journal Research Supplement
, Vol.
63
, No.
6
,
1984
, pp. 173s–183s.
15.
Westgate
,
S. A.
and
Threadgill
,
P. L.
, “
Properties of Flash-Butt Welded Carbon-Manganese Steel-Influence of Power Supply and Welding Conditions
,” Research Report 208/1983,
The Welding Institute
, Cambridge, England,
03
1983
.
16.
Landes
,
J. D.
, “
Predicting and Influencing Fracture Toughness of Steels in the Transition
,”
Proceedings
, Vol.
II
, Fifth International Offshore Mechanics and Arctic Engineering Symposium,
Tokyo, Japan
,
1986
,
American Society of Mechanical Engineers
,
New York, NY
,
1986
, pp. 161–167.
17.
Watanabe
,
J.
,
Iwadate
,
T.
,
Tanaka
,
Y.
, and
Yokobori
,
T.
, “
Fracture Toughness in the Transition Region
,”
Engineering Fracture Mechanics
 0013-7944, Vol.
28
, No.
5/6
,
1987
, pp. 589–600.
18.
Rosenfield
,
A. R.
and
Sketty
,
D. K.
, “
Cleavage Fracture of Steel in the Ductile-Brittle Transition Region
,”
Elastic-Plastic Fracture Test Methods: The User's Experience
, ASTM STP 856,
American Society for Testing and Materials
,
1985
, pp. 196–209.
19.
Willoughby
,
A. A.
,
Pratt
,
P. L.
, and
Turner
,
C. E.
, “
The Meaning of Elastic-Plastic Fracture Criteria During Slow Crack Growth
,”
International Journal of Fracture
, Vol.
17
, No.
5
,
1981
, pp. 449–466.
20.
Chen
,
J. H.
and
Yan
,
C.
, “
Fracture Behavior of C-Mn Steel Multipass MMA Weld Metals at-60°C in Charpy V Testing
,”
Materials Science and Technology
 0267-0836, Vol.
4
, No.
8
,
1988
, pp. 732–739.
21.
Zhang
,
X. J.
,
Armstrong
,
R. W.
, and
Irwin
,
G. R.
, “
Cleavage Fracturing Stages at Micrometer-Size Inclusions in Pressure Vessel Steel Weld Metal
,”
Journal of Materials Science Letters
 0022-2461, Vol.
5
, No.
10
,
1986
, pp. 961–964.
22.
Khan
,
M. A.
,
Shoji
,
T.
, and
Takahasi
,
H.
, “
Acoustic Emission from Cleavage Microcracking in Alloy Steels
,”
Metal Science
,
1982
, Vol.
16
, pp. 118–126.
23.
Hou
,
C. X.
,
Cai
,
Q. G.
,
Su
,
Y.
, and
Zheng
,
X. Y.
, “
Volume Effect on Cleavage Strength, Microstructure, and Fracture Micromechanism of Welded 15MnVN Steel
,”
Advances in Fracture Research, Proceedings
, Sixth International Conference on Fracture,
New Delhi, India
,
Valluri
S. R.
et al, Eds.,
Pergamon Press
,
New York
,
1984
, pp. 1415–1422.
24.
Satoh
,
K.
,
Toyada
,
M.
, and
Minami
,
F.
, “
A Probabilistic Approach to Evaluation of Fracture Toughness in Welds with Heterogeneity
,”
Quality and Reliability in Welding, Proceedings
, International Conference on Quality and Reliability in Welding,
Hangzhou, China
,
1984
,
The Welding Institute of the Chinese Mechanical Engineering Society
,
Beijing, China
, pp. C-4-1 to C-4-6.
25.
Anderson
,
T. L.
,
McHenry
,
H. I.
, and
Dawes
,
M. G.
, “
Elastic-Plastic Fracture Toughness Tests with Single-Edge Notched Bend Specimens
,”
Elastic-Plastic Fracture Test Methods: The User's Experience
, ASTM STP 856,
American Society for Testing and Materials
,
1985
, pp. 210–229.
26.
Knott
,
J. F.
, “
Strength and Toughness of Steel
,”
Advances in the Physical Metallurgy and Applications of Steels
,
The Metals Society
,
London, England
,
1981
, pp. 181–198.
27.
Saldanha Peres
,
J.
and
Fernandes
,
A. A.
, “
Influence of the Weld Metal Toughness on the Reliability of an Offshore Structure
,”
Welding of Tubular Structures
,
IIW Annual Assembly
,
Boston
,
07
1984
.
28.
Terlinde
,
G.
,
Muller
,
L.
,
Beaven
,
P. A.
, and
Schwalbe
,
K. H.
, “
Microstructure Effects on the Toughness of FCAW-Ferrite Weld Metal
,”
Proceedings
, Fifth European Conference on Fracture (ECF-5), Sociedade Portuguesa de Materiais,
Faria
L.
, Ed.,
Seccao, Tecnica Fractura
,
Lisbon, Portugal
,
1984
, pp. 257–268.
29.
Shiliang
,
W.
,
Weiping
,
Hu
, and
Bogang
,
T.
, “
Improving the Toughness of Weld Metal by Adding Rare Earth Elements
,”
Welding International
, Vol.
1
, No.
3
,
1987
, pp. 284–287;
Shiliang
,
W.
,
Weiping
,
Hu
, and
Bogang
,
T.
, translation from
Trans China Weld Institute
, Vol.
7
, No.
2
,
1986
, pp. 56–63.
30.
Tweed
,
J. H.
and
Knott
,
J. F.
, “
Micromechanisms of Failure in C-Mn Weld Metals
,”
Acta Metallurgica
 0001-6160, Vol.
35
, No.
7
,
1987
, pp. 1401–1414.
31.
Tweed
,
J. H.
and
Knott
,
J. F.
, “
Effect of Reheating on Microstructure and Toughness of C-Mn Weld Metal
,”
Metal Science
, Vol.
17
, No.
2
,
1983
, pp. 45–54.
32.
Rice
,
J. R.
and
Johnson
,
M. A.
in
Inelastic Behavior of Solids
,
Kanninen
M. F.
, Ed.,
McGraw-Hill
,
New York
,
1970
, pp. 641–669.
33.
Knott
,
J. F.
, “
Sources of Scatter in Fracture Toughness Values and in Fatigue Crack Propagation Rates
,”
Fracture and the Role of Microstructure, Proceedings
, Fourth European Conference on Fracture,
Loeben, Austria
,
Maurer
K. L.
and
Matzer
F. E.
, Eds.,
Engineering Materials Advisory Services Limited
,
Warley, England
,
1982
, pp. 221–227.
34.
Curry
,
D. A.
, “
Cleavage Micromechanisms of Crack Extension in Steels
,”
Metal Science
, Vol.
14
, Nos.
8
and
9
,
1980
, pp. 319–326.
35.
Curry
,
D. A.
and
Knott
,
J. F.
, “
Effect of Microstructure on Cleavage Fracture Toughness of Quenched and Tempered Steels
,”
Metal Science
, Vol.
13
, No.
6
,
1979
, pp. 341–345.
36.
Xu
,
X. X.
,
Cai
,
Q. G.
,
Su
,
Y.
,
Hou
,
C. X.
, and
Ma
,
W. D.
, “
A Statistical Model of Cleavage Fracture in the Granular Bainite in the Simulated Weld Heat-Affected Zone
,”
Materials Science and Technology
 0267-0836, Vol.
5
, No.
9
,
1989
, pp. 913–917.
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