On the Utilization of High Rate Pre-Cracked Charpy Test Results and the Master Curve to Obtain Accurate Lower Bound Toughness Predictions in the Ductile-to-Brittle Transition

2009 ◽  
pp. 253-253-21 ◽  
Author(s):  
JA Joyce
Keyword(s):  
Lower Bound ◽  
Master Curve ◽  
High Rate ◽  
Test Results ◽  
Charpy Test ◽  
Brittle Transition ◽  
Ductile To Brittle Transition

Analysing the Notch Effect Within the Ductile-to-Brittle Transition Zone of S275JR Steel

2013 ◽  
Author(s):  
Sergio Cicero ◽  
Tiberio García ◽  
Virginia Madrazo ◽  
Jorge Cuervo ◽  
Estela Ruiz ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Bearing Capacity ◽  
Transition Zone ◽  
Master Curve ◽  
Notch Effect ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Brittle Transition ◽  
Apparent Fracture Toughness ◽  
Ductile To Brittle Transition

This paper analyses the notch effect in ferritic-pearlitic steel S275JR in a range of temperatures within the material Ductile-to-Brittle Transition Zone (DBTZ). The notch effect is evaluated in terms of load-bearing capacity, apparent fracture toughness (modeled here using the Theory of Critical Distances) and fracture micromechanisms. The concept of Master Curve in notched conditions is also presented. To this end, experimental results obtained in S275JR notched specimens are presented, together with Scanning Electron Microscopy (SEM) fractographies. The analysis is performed at −50 °C, −30 °C and −10 °C, the material Transition Temperature (T0) being −26.1 °C, with the notch radii ranging from 0 mm (crack-type defects) up to 2.0 mm. The results show how the lower the temperature the larger the notch effect, and also that the evolution of both the load bearing capacity and the apparent fracture toughness is directly related to the evolution of fracture micromechanisms. Moreover, the proposed Master Curve in notched conditions has provided good predictions of the experimental results.

On the Use of the Notch Master Curve for Apparent Fracture Toughness Predictions of Notched Ferritic Steels Operating Within the Ductile-to-Brittle Transition Zone

2015 ◽  
Author(s):  
Sergio Cicero ◽  
Tiberio Garcia ◽  
Virginia Madrazo
Keyword(s):  
Fracture Toughness ◽  
Transition Zone ◽  
Fracture Resistance ◽  
Master Curve ◽  
Ferritic Steels ◽  
Brittle Transition ◽  
Apparent Fracture Toughness ◽  
Different Temperatures ◽  
Fracture Tests ◽  
Ductile To Brittle Transition

This paper presents the Notch-Master Curve as a model for the prediction of the apparent fracture toughness of ferritic steels in notched conditions and operating at temperatures corresponding to their ductile-to-brittle transition zone. The Notch-Master Curve combines the Master Curve of the material in cracked conditions and the notch corrections provided by the Theory of Critical Distances. In order to validate the model, the fracture resistance results obtained in fracture tests performed on notched CT and SENB specimens are presented. The results gathered here cover four ferritic steels (S275JR, S355J2, S460M and S690Q), three different notch radii (0.25 mm, 0.50 mm and 2.0 mm) and three different temperatures within the corresponding ductile-to-brittle transition zone. The results demonstrate that the Notch Master Curve provides good predictions of the fracture resistance in notched conditions for the four materials analyzed.

Effect of Microstructure Degradation on Fracture Toughness of 20MnMoNi55 Steel in DBT Region

2016 ◽  
Vol 6 (3) ◽  
pp. 11-27
Author(s):  
Sumit Bhowmik ◽  
Prasanta Sahoo ◽  
Sanjib Kumar Acharyya ◽  
Sankar Dhar ◽  
Jayanta Chattopadhyay
Keyword(s):  
Fracture Toughness ◽  
Master Curve ◽  
Temperature Curve ◽  
Metallic Alloys ◽  
Reference Temperature ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Brittle Transition ◽  
Ductile To Brittle Transition ◽  
Effect Of Microstructure

The paper considers the effect of microstructure degradation on fracture toughness of 20MnMoNi55 pressure vessel steel. This degradation is reflected through the shift of fracture toughness vs. temperature curve along the temperature axis and rise in reference temperature in ductile to brittle transition (DBT) region. Hardness also depends on the microstructure of metallic alloys. The present study explores the correlation between hardness and fracture toughness for different microstructures in order to calibrate loss in toughness from hardness. The master curve reference temperature and microhardness for different microstructures are measured experimentally. It is observed that there exists a fair linear relation between microhardness and reference temperature.

A Method to Derive the JC Value of a 1T SE(B) Using Charpy Impact Energy in the Lower Ductile to Brittle Transition

2015 ◽  
Author(s):  
Robin J. Smith ◽  
Andrew H. Sherry ◽  
Anthony J. Horn ◽  
Adam C. Bannister
Keyword(s):  
Test Data ◽  
Impact Energy ◽  
Experimental Test ◽  
Ferritic Steel ◽  
Charpy Impact ◽  
Fracture Toughness Test ◽  
Test Results ◽  
Brittle Transition ◽  
Wide Range ◽  
Ductile To Brittle Transition

This paper describes a method by which the elastic-plastic crack driving force, J, of a 1T SE(B) may be calculated using Charpy V-notch absorbed impact energy, Uel+pl,LLD. The method is applicable in the lower ductile-to-brittle transition regime of fracture behaviour and permits the calculation of equivalent critical J-integral values, Jc, using Uel+pl,LLD data. The method is demonstrated using a ferritic steel study material. Comparisons are made between the predictions of a Uel+pl,LLD scaling approach, which was derived using a Weibull stress model, and experimental test data for a ferritic steel. The approach was evaluated using experimental test data composed of instrumented Charpy impact test results and SE(B) fracture toughness test results. The probabilistic predictions were found to be in good agreement with experimental values. Extension of the methodology is recommended to include other material flow properties. Further work is required to ascertain the accuracy of the approach at higher temperatures in the ductile-to-brittle transition temperature range. A practical method for applying the methodology in practice to allow description of the behaviour of a wide range of ferritic steel materials has been outlined.

Variation of Beremin Model Parameters With Temperature by Monte Carlo Simulation

2019 ◽  
Vol 141 (2) ◽  
Author(s):  
K. Bhattacharyya ◽  
S. Acharyya ◽  
S. Dhar ◽  
J. Chattopadhyay
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Master Curve ◽  
Model Parameters ◽  
Three Point Bending ◽  
Brittle Transition ◽  
Different Temperatures ◽  
Ductile To Brittle Transition ◽  
Vessel Material ◽  
Reactor Pressure

In this work, variation of the Beremin parameters with temperature for reactor pressure vessel material 20MnMoNi55 steel is studied. Beremin model is used, including the effect of plastic strain as originally formulated in the Beremin model. A set of six tests are performed at a temperature of −110 °C in order to determine reference temperature (T0) and master curve for the entire ductile-to-brittle transition (DBT) region as per the ASTM Standard E1921. Monte Carlo simulation is employed to produce a large number of 1 T three-point bending specimen (TPB) fracture toughness data randomly drawn from the scatter band obtained from the master curve, at different temperatures of interest in the brittle dominated portion of DBT region to determine Beremin model parameters variation with temperatures.

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