On the temperature dependence of fracture toughness in the brittle-to-ductile transition region

1999 ◽  
Vol 35 (4) ◽  
pp. 398-404 ◽  
Author(s):  
A. A. Kaminskii ◽  
G. V. Galatenko
Keyword(s):  
Fracture Toughness ◽  
Temperature Dependence ◽  
Transition Region ◽  
Brittle To Ductile Transition

Observations Arising From Exponential Fitting Methods to a Charpy V-Notch Energy Database From Tata Steel

2011 ◽  
Author(s):  
Anthony J. Horn ◽  
Thomas M. Axe
Keyword(s):  
Fracture Toughness ◽  
Temperature Dependence ◽  
Transition Region ◽  
Pressure Vessel ◽  
Mathematical Expression ◽  
Exponential Fitting ◽  
Wide Range ◽  
Pressure Vessel Steels ◽  
Exponential Temperature Dependence ◽  
Region Data

Charpy testing across a range of temperatures is a cost effective way to characterise the ductile-to-brittle transition region. It is often convenient to fit a curve to Charpy data through the transition region: a commonly used method is to use a continuous tan-h fit, a single mathematical expression that links lower shelf, transition region and ductile upper shelf behaviour in one continuous curve. Using this method, the temperature dependence of Charpy energy is a unique feature of each individual steel with some steels exhibiting steep transition curves and some shallow curves. In contrast to Charpy data, fracture toughness data are usually analysed by partitioning upper shelf and transition region data. The transition region data is generally accepted to fit a universal temperature dependence, the Master Curve, as proposed by Wallin [1] and standardised in ASTM E1921 [2]. Recent research on nuclear pressure vessel steels [3, 4] has indicated that when Charpy data is assessed using a similar method to that used for fracture toughness data, a common exponential temperature dependence is observed. This paper presents the current results from an on-going investigation aimed at assessing the effect of exponential curve fitting methods on a large dataset of Charpy V-notch energy data from Tata Steel. The Tata Steel data cover a wide range of parent plate steels. The results are compared to the recent studies on nuclear pressure vessel steels and a similar exponential temperature dependence is observed.

A study on fracture toughness of potassium dihydrogen phosphate single crystals

CrystEngComm ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 1329-1334 ◽  
Author(s):  
Pingping Huang ◽  
Jianxu Ding ◽  
Duanliang Wang ◽  
Hui Liu ◽  
Longyun Xu ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Potassium Dihydrogen ◽  
Brittle To Ductile Transition ◽  
Kdp Crystals

The results of the temperature dependence of fracture toughness of KDP crystals with four orientations show that the brittle-to-ductile transition occurs at 160 °C.

scholarly journals Investigation of Fracture Process of S355JR Steel in Transition Region Using Metallographic and Fractographic Tests and Numerical Analysis

2018 ◽  
Vol 12 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Ihor Dzioba ◽  
Sebastian Lipiec ◽  
Piotr Furmanczyk ◽  
Robert Pala
Keyword(s):  
Transition Region ◽  
Fracture Process ◽  
Test Results ◽  
Transition Range ◽  
Plastic Properties ◽  
Brittle To Ductile Transition ◽  
Edge Notch ◽  
Fractographic Examination ◽  
Electronic Microscope ◽  
Senb Specimen

Abstract In the paper are presented test results of fracture process in brittle-to-ductile transition range for two microstructural types of S355JR steel – ferrite-pearlite and ferrite-carbides. For both kinds of S355JR steel obtained in temperature range of transition region the strength and plastic properties are similar, but the fracture toughness characteristics showed significantly are various. To clarify the differences in the course of trends in the mechanical characteristics performed metallographic and fractographic observations using the scanning electronic microscope. The fractographic examination showed that changes in the fracture surface morphology were dependent on the test temperature. It was also found that during the subcritical crack growth the region of ductile fracture extension reduced with decreasing temperature. The results of finite element method (FEM) calculation the stress fields in front of the crack of single edge notch in bending (SENB) specimens in the range of brittle-to-ductile transition are presented also. The FEM calculations were performed on the numerical model of SENB specimen using the ABAQUS program.

A Monte Carlo Implementation of the James-Ford-Jivkov Microstructurally Informed Local Approach Applied to Predict Fracture Toughness Across Irradiation Conditions

2016 ◽  
Author(s):  
Michael Ford ◽  
Peter James
Keyword(s):  
Fracture Toughness ◽  
Monte Carlo ◽  
Transition Region ◽  
Crack Size ◽  
Model Parameters ◽  
Pressure Vessel Steel ◽  
Local Approach ◽  
Vessel Steel ◽  
Reactor Pressure Vessel Steel ◽  
Monte Carlo Implementation

The need to predict changes in fracture toughness for materials where the tensile properties change through life, such as with irradiation, whilst accounting for geometric constraint effects, such as crack size, are clearly important. Currently one of the most likely approaches by which to develop such ability are through application of local approach models. These approaches appear to be sufficient in predicting lower shelf toughness under high constraint conditions, but may fail when attempting to predict toughness in the transition region, for low constraint geometries or for different irradiation states, when using the same parameters, making reliable predictions impossible. Cleavage toughness predictions in the transition regime are here made with a stochastic, Monte Carlo implementation of the recently proposed James-Ford-Jivkov model. This implementation is based around the creation of individual initiators following the experimentally observed distribution for specific reactor pressure vessel steel, and determining if these initiators form voids or cause cleavage failure using the model’s improved criterion for particle failure. This implementation has been presented previously in PVP2015-45905, where it was successfully applied across different constraint conditions; in the work presented here it is applied across different irradiation conditions for a second type of steel. The model predicts the fracture toughness in a large part of the transition region, demonstrates an ability to predict the irradiation shift and shows a level of scatter similar to that observed experimentally. All results presented, for a given material, are obtained without changes in the model parameters. This suggests that the model can be used predicatively for assessing toughness changes due to constraint-, irradiation- and temperature-driven plasticity changes.

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