Abstract

In 2019, the ASTM E08.07.06 subcommittee added a homogeneity screening procedure to ASTM E1921, Standard Test Method for Determination of Reference Temperature, To, for Ferritic Steels in the Transition Range. The screening procedure is intended to determine if the data set may be representative of a macroscopically inhomogeneous material. If the material fails the screening criterion, the subcommittee added Appendix X5, “Treatment of Potentially Inhomogeneous Data Sets,” to enable more accurate assessment of the material. Several existing large fracture toughness data sets of reactor pressure vessel low alloy steel plates, forgings, and welds were assembled to evaluate the homogeneity screening procedure and the Appendix X5 treatment methods. Several subsets of data from each of the large data sets were separately evaluated. The small data subsets are intended to approximate the number of specimens generally tested for an irradiated material (typically less than 20). The data set is screened and, if found inhomogeneous, treated according to the procedure in Appendix X5 that applies to small subsets of data. The results from the various subsets are compared with the parent large data set to assess the ability of the least conservative data subsets to bound the full data set. It is shown that, depending on the screening outcome, different margin adjustments than those recommended in ASTM E1921-20 can be used to provide results that bound a high percentage of the data. In addition, the experience presented in interpreting and using the procedures for the various data subsets has provided valuable insight for future applications.

References

1.
Standard Test Method for Determination of Reference Temperature, To, for Ferritic Steels in the Transition Range
, ASTM E1921-20 (
West Conshohocken, PA
:
ASTM International
, approved June 1,
2020
), https://doi.org/10.1520/E1921-20
2.
Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels Section XI, Division 1
, ASME Boiler and Pressure Vessel Code Case N‐830, Section XI, Supplement 7, 2013 Edition (
New York
:
American Society of Mechanical Engineers
, approved September 4,
2014
).
3.
Use of Fracture Toughness Test Data to Establish Reference Temperature for Pressure Retaining Materials
, ASME Boiler and Pressure Vessel Code Case N-629, Section XI, Division 1 (
New York
:
American Society of Mechanical Engineers
, approved May 7,
1999
).
4.
Alternative Method for Establishing the Reference Temperature for Pressure Retaining Materials
, ASME Boiler and Pressure Vessel Code Case N-851, Section XI, Division 1 (
New York
:
American Society of Mechanical Engineers
, approved November 5,
2014
).
5.
Fracture Toughness Criteria for Protection against Failure
, ASME Boiler and Pressure Vessel Code, Section XI, Division 1, Appendix G (
New York
:
American Society of Mechanical Engineers
, approved
2013
).
6.
Yamamoto
M.
,
Onizawa
K.
,
Yoshimoto
K.
,
Ogawa
T.
,
Mabuchi
Y.
,
Valo
M.
,
Lambrecht
M.
,
Viehrig
H.-W.
,
Miura
N.
, and
Soneda
N.
, “
International Round Robin Test on Master Curve Reference Temperature Evaluation Utilizing Miniature C(T) Specimen
,” in
Small Specimen Test Techniques: Sixth Volume
, ed.
Sokolov
M. A.
and
Lucon
E.
(
West Conshohocken, PA
:
ASTM International
,
2015
),
53
69
, https://doi.org/10.1520/STP1576-EB
7.
McCabe
D. E.
,
Nanstad
R. K.
,
Iskander
S. K.
,
Heatherly
D. W.
, and
Swain
R. L.
,
Evaluation of WF-70 Weld Metal from the Midland Unit 1 Reactor Vessel, NUREG/CR-5736
(
Washington, DC
: U
.S. Nuclear Regulatory Commission
,
2000
).
8.
Yamamoto
M.
, “
Trial Study of the Master Curve Fracture Toughness Evaluation by Mini-C(T) Specimens for Low Upper Shelf Weld Metal Linde-80
,” in
Proceedings of the ASME 2018 Pressure Vessels and Piping Conference
(
New York
:
American Society of Mechanical Engineers
,
2018
),
PVP2018
84906
, https://doi.org/10.1115/PVP2018-84906
9.
Sokolov
M. A.
, “
Use of Mini-C(T) Specimens for Fracture Toughness Characterization of Low Upper-Shelf Linde 80 Weld before and after Irradiation
,” in
Proceedings of the ASME 2018 Pressure Vessels and Piping Conference
(
New York
:
American Society of Mechanical Engineers
,
2018
),
PVP2018
84804
, https://doi.org/10.1115/PVP2018-84804
10.
Ickes
M. R.
,
Hall
J. B.
, and
Carter
R. G.
, “
Fracture Toughness Characterization of Low Upper-Shelf Linde 80 Weld Using Mini-C(T) Specimens
,” in
Proceedings of the ASME 2018 Pressure Vessels and Piping Conference
(
New York
:
American Society of Mechanical Engineers
,
2018
),
PVP2018
84967
, https://doi.org/10.1115/PVP2018-84967
11.
Server
W.
,
Sokolov
M.
,
Yamamoto
M.
, and
Carter
R.
, “
Inter-Laboratory Results and Analyses of Mini-C(T) Specimen Testing of an Irradiated Linde 80 Weld Metal
,” in
Proceedings of the ASME 2018 Pressure Vessels and Piping Conference
(
New York
:
American Society of Mechanical Engineers
,
2018
),
PVP2018
84950
, https://doi.org/10.1115/PVP2018-84950
12.
Nanstad
R. N.
,
Haggag
F. M.
,
McCabe
D. E.
,
Islander
S. K.
,
Bowman
K. O.
, and
Menke
B. H.
,
Irradiation Effects on Fracture Toughness of Two High-Copper Submerged Arc Welds, HSSI Series 5, NUREG/CR-5913, ORNL/TM-12156N/V1
(
Washington, DC
:
U.S. Nuclear Regulatory Commission
,
1992
).
13.
Van Der Sluys
W. A.
, and
Miglin
M. T.
, “
Results of MPC/JSPS Cooperative Testing Program in the Brittle-to-Ductile Transition Region
,” in
Fracture Mechanics: 24th Volume
, ed.
McCabe
D. E.
and
Boulet
J. A. M.
(
West Conshohocken, PA
:
ASTM International
,
1994
),
308
324
, https://doi.org/10.1520/STP1207-EB
14.
Lucon
E.
and
Scibetta
M.
,
Application of Advanced Master Curve Approaches to the EURO Fracture Toughness Data Set
, Open Report BLG-1036 (
Mol, Belgium
:
SCK-CEN, Belgian Nuclear Research Centre
,
2007
).
15.
McCabe
D. E.
,
A Comparison of Weibull and βic Analysis of Transition Range Fracture Toughness Data, NUREG/CR-5788
(
Oak Ridge, TN
:
Oak Ridge National Laboratory
,
1992
).
16.
VanDerSluys
W. A.
,
Hoffmann
C. L.
,
Yoon
K. K.
,
Killian
D. E.
, and
Hall
J. B.
,
Fracture Toughness Master Curve Development: Fracture Toughness of Ferritic Steels and ASTM Reference Temperature (To), WRC Bulletin 457
(
New York
:
Welding Research Council
,
2000
).
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