Variations in Charpy Impact Data Evaluated by a Round-Robin Testing Program — A Summary

2009 ◽  
pp. 487-487-13
Author(s):  
AL Lowe
Keyword(s):  
Charpy Impact ◽  
Round Robin ◽  
Testing Program ◽  
Impact Data

Microstructure-Toughness Relationship in AISI4340 Steel

2011 ◽  
Vol 312-315 ◽  
pp. 110-115
Author(s):  
N. Saeidi ◽  
A. Ekrami
Keyword(s):  
Transition Temperature ◽  
Charpy Impact ◽  
Brittle Transition ◽  
Hardness Tests ◽  
Ductile Brittle Transition Temperature ◽  
Different Temperatures ◽  
Ferrite Steel ◽  
Brittle Transition Temperature ◽  
Impact Data ◽  
Aisi4340 Steel

To improve the strength and toughness of AISI 4340 steel, different microstructures, containing full bainite, bainite-ferrite, martensite-ferrite and full martensite were produced by different heat treatment cycles. Tensile, impact and hardness tests were carried out at room temperature. The ductile-brittle transition temperature was determined from impact data at different temperatures. The results showed that steel with bainite - 0.34 ferrite microstructure has the highest elongation and charpy impact energy, while its tensile strength and yield stress decreased in comparison to other microstructures. This increment was noticeable when bainite - 0.34 ferrite steel was tempered. The ductile-brittle transition temperature decreased with tempering of bainite -0.34 steel. The fracture surface analysis of charpy specimens also showed an increase in toughness of tempered bainite-ferrite in comparison to other microstructures.

Predicting the Brittle-to-Ductile Fracture Initiation Transition Temperature for Surface-Cracked Pipe From Charpy Data

2005 ◽  
Author(s):  
Gery Wilkowski ◽  
Dave Rudland ◽  
Richard Wolterman
Keyword(s):  
Transition Temperature ◽  
Ductile Fracture ◽  
Failure Modes ◽  
Charpy Impact ◽  
Fracture Initiation ◽  
Evaluation Procedures ◽  
Balance Of Plant ◽  
Constraint Effects ◽  
Impact Data ◽  
Ductile Fracture Initiation

Much work has been done to assess constraint effects on the crack-driving force for specimens and cracks in pipes. The material’s transition temperature where the fracture process changes from ductile tearing to cleavage fracture at crack initiation is affected by the constraint conditions, but is a material property that cannot be determined analytically. This paper presents a methodology to account for constraint effects to predict the lowest temperature for ductile fracture initiation and relates that temperature to Charpy impact data for typical ferritic pipe materials. It involves a series of transition temperature shifts to account for thickness, strain-rate, and constraint to give a master curve of transition temperatures from Charpy data to through-wall-cracked or surface-cracked pipes (with various a/t values) under quasi-static loading. These transition temperature shifts were based on hundreds of pipe tests and thousands of specimen tests over several decades of work by numerous investigators. It is equally applicable to ferritic nuclear pipe for Class 2, 3, or balance of plant piping, or for older linepipe materials. If found to be reasonable, then the procedure could be used in the ASME pipe flaw evaluation procedures as a screening criterion between LEFM and EPFM failure modes.

A Round Robin Testing Program to Estimate the Precision of ASTM C518 for Measuring the k-Factor of Rigid Foam Product

1991 ◽  
Vol 14 (3) ◽  
pp. 184-194 ◽  
Author(s):  
S.A. Smith ◽  
J.J. Lynch ◽  
M.L. Moore ◽  
C.J. Galbraith
Keyword(s):  
Round Robin ◽  
Testing Program ◽  
Rigid Foam ◽  
K Factor

CURVE FITTING IN THE TRANSITION REGION OF CHARPY IMPACT DATA

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1496-1503 ◽  
Author(s):  
HYUNG-SEOP SHIN ◽  
JONG-SEO PARK ◽  
HAE-MOO LEE
Keyword(s):  
Transition Region ◽  
Research Work ◽  
Charpy Impact ◽  
Data Fitting ◽  
Hyperbolic Function ◽  
Impact Tests ◽  
Fitting Procedure ◽  
General Mathematical Model ◽  
Fitting In ◽  
Impact Data

The toughness data obtained from Charpy impact tests are presented by a temperature-energy relationship. Data fitting for quantitative evaluation of the transition temperature, upper shelf energy and ductile-brittle transition, in other words, the representation with general mathematical model equation for energy variation according to the temperature is necessary. In this study, the Charpy impact tests to two representative steels were carried out as a research work for the material property standardization technique development. The fitting procedure of the scattering in data according to materials and temperature in the transition region was described. The data fitting procedure using the tangent hyperbolic function was established through variances treatment in the transition region.

Application of the Master Curve Method to the Japanese RPV Materials

2005 ◽  
Author(s):  
Hiroomi Funakoshi ◽  
Yasushi Kanazawa ◽  
Takashi Hirano ◽  
Naoki Kojima ◽  
Kouichi Matsumoto ◽  
...  
Keyword(s):  
Master Curve ◽  
Charpy Impact ◽  
Pressure Vessels ◽  
Surveillance Program ◽  
Master Curve Method ◽  
Curve Method ◽  
Static Fracture ◽  
Impact Data ◽  
Reactor Pressure ◽  
Mc Method

In application of the Master Curve (MC) method to the surveillance program of the BWR plants in Japan, we need to address two issues. The first one is to confirm the validity of the MC method to the steels typical to the Japanese reactor pressure vessels (RPVs), and the second is to find a procedure, which allows us to smoothly switch from the current Charpy-based surveillance program to the MC-based surveillance program. In this study, we present results to address the two different issues mentioned above. First, we study the application of the ASTM E 1921 procedure to determine the To values and the MCs for the unirradiated model steels for the Japanese BWR plants. We investigate the basic aspects of the MC method. Second, we investigate the applicability of instrumented Charpy impact data to estimate static fracture toughness Jc values.

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