Charpy V notch tests – Risks associated with testing with 3 samples

To estimate the risk of brittle fracture of a component in service, Charpy tests are generally carried out on 3 samples at the same temperature. Work done over many years on welded joint fatigue using probability and statistics has shown that to have a good assessment of minimum strength, it is clearly necessary to have a larger number of test results. In order to analyse the risks associated with this practice of 3 samples tested at the same temperature, a series of 17 Charpy impact test results of samples of the same steel plate was chosen. From this series, by translation, 2 series were generated, one with a test of 3 specimens showing acceptable steel and one with a test of 3 specimens showing unacceptable steel. The 3-test method was applied to these series leading to a possible simulation of 12 tests each. It was found that the 3-test practice leads to a risk of error of 30 to 40%. It is also found that the determination of the transition curve of a DH36 steel finally shows that its temperature for a CV of 27 J is of the order of −50 °C whereas the regulations require only −20 °C. In conclusion, a possible improvement of the test procedure is indicated, which is the subject of a study within the framework of the “CCRS rupture and fatigue” working groups of the Société des Ingénieurs Soudeurs (SIS).

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Study of mechanical properties of indium-based solder alloys for cryogenic applications

Soldering & Surface Mount Technology ◽

10.1108/ssmt-10-2021-0065 ◽

2022 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Madhuri Chandrashekhar Deshpande ◽

Rajesh Chaudhari ◽

Ramesh Narayanan ◽

Harishwar Kale

Keyword(s):

Mechanical Properties ◽

Solder Alloy ◽

Charpy Impact ◽

Charpy Impact Test ◽

Test Results ◽

Solder Alloys ◽

Content Type ◽

Electron Microscope Analysis ◽

American Society ◽

Work Done

Purpose This study aims to develop indium-based solders for cryogenic applications. Design/methodology/approach This paper aims to investigate mechanical properties of indium-based solder formulations at room temperature (RT, 27 °C) as well as at cryogenic temperature (CT, −196 °C) and subsequently to find out their suitability for cryogenic applications. After developing these alloys, mechanical properties such as tensile and impact strength were measured as per American Society for Testing and Materials standards at RT and at CT. Charpy impact test results were used to find out ductile to brittle transition temperature (DBTT). These properties were also evaluated after thermal cycling (TC) to find out effect of thermal stress. Scanning electron microscope analysis was performed to understand fracture mechanism. Results indicate that amongst the solder alloys that have been studied in this work, In-34Bi solder alloy has the best all-round mechanical properties at RT, CT and after TC. Findings It can be concluded from the results of this work that In-34Bi solder alloy has best all-round mechanical properties at RT, CT and after TC and therefore is the most appropriate solder alloy amongst the alloys that have been studied in this work for cryogenic applications Originality/value DBTT of indium-based solder alloys has not been found out in the work done so far in this category. DBTT is necessary to decide safe working temperature range of the alloy. Also the effect of TC, which is one of the major reasons of failure, was not studied so far. These parameters are studied in this work.

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Fracture Toughness and Charpy Impact Test of MIM Steels and Correlation of Results by KIC- CVN Relationships

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.810.1 ◽

2019 ◽

Vol 810 ◽

pp. 1-6

Author(s):

Radek Tomášek ◽

Vratislav Mareš ◽

Lukáš Horsák

Keyword(s):

Fracture Toughness ◽

Charpy Impact ◽

Charpy Impact Test ◽

Impact Testing ◽

Test Method ◽

Transition Curve ◽

Fracture Toughness Test ◽

Average Deviation ◽

Charpy Impact Testing ◽

Shelf Region

This paper presents results of fracture toughness and Charpy impact tests of 4 steels prepared by metal injection moulding (MIM) method: AISI 4140, 4605, 17-4 PH and SS 420W Grade. Charpy impact testing was performed on the series of machined specimens with sub-size cross-section to obtain values of CVN impact energy. Fracture toughness test method according to ASTM E1820 was performed on SENB specimens, fatigue pre-cracked, to obtain values of KIC. All tests were performed at the room temperature. After the material testing, next step was to evaluate the results and apply known correlation relationships between fracture toughness KIC and Charpy impact CVN energies. Many empirical relations exist and describe existence of such relationship. Procedure was used to correlate energies of sub-size Charpy specimens to full-size specimens. Several proposed correlation relationships from transition and upper shelf region of transition curve were used, where the best correlation was found to be Robert-Newtons with average deviation of 22% in comparison to tested values.

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Influence of Specimen Geometry and Strain Rate on Ductile-Brittle Transition Characterisation of Reactor Pressure Vessel Steels Using the Small Punch Technique

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2015-45373 ◽

2015 ◽

Cited By ~ 2

Author(s):

Jack Adams ◽

Roger C. Hurst ◽

J. Bryan Borradaile ◽

Martin R. Bache

Keyword(s):

Strain Rate ◽

Health And Safety ◽

Charpy Impact ◽

Charpy Impact Test ◽

Transition Curve ◽

Charpy Test ◽

Small Punch ◽

Code Of Practice ◽

Brittle Transition ◽

Post Test

The small punch (SP) tensile test, originally developed for assessing the integrity of nuclear containments, has seen a renaissance in recent years with the introduction of a Code of Practice and a standardisation proposal. For nuclear applications, the extremely low volumes of material that are required allows specimens to be manufactured from quasi-destructive scoop samples, surveillance specimens or even previously tested Charpy specimens. The low volume of material also alleviates the health and safety requirements and the cost associated with testing active materials. By assessing the energy absorbed before fracture, it is possible to build an entire SP ductile-brittle transition curve using less material than is required for a single Charpy test. Small punch testing has been performed on SA 508-3 NESC-1 spinning cylinder material to establish ductile-brittle transition data, for comparison to that obtained by conventional Charpy impact test techniques. Multiple SP ductile-brittle transition curves have been constructed, building upon the framework of the existing Code of Practice. Novel geometries and associated machining techniques employed to incorporate notches into the surface of the SP specimen, and also the application of relatively high strain rates have been investigated. Post-test fractography illustrates the influence of both stress raising features and strain rate on small punch fracture behaviour.

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Verification of the Charpy Impact Test Capability to Determine the Constants of the Johnson-Cook Model

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.250.197 ◽

2016 ◽

Vol 250 ◽

pp. 197-202 ◽

Cited By ~ 1

Author(s):

Michal Stopel Stopel ◽

Dariusz Skibicki

Keyword(s):

Experimental Test ◽

Impact Test ◽

Charpy Impact ◽

Material Model ◽

Charpy Impact Test ◽

Feasibility Analysis ◽

Model Parameters ◽

Strain Rates ◽

Split Hopkinson

Feasibility analysis of replacing split Hopkinson bars test by Charpy impact test for determination of Johnson-Cook’s material model parameters. The results show that the Charpy impact test may, due to the strain rates achieved, successfully replace the mentioned experimental test. Moreover the results shows that some further studies should be conducted to improve efficiency of the proposed method.

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Determination of Johnson–Cook parameters and evaluation of Charpy impact test performance for X80 pipeline steel

International Journal of Mechanical Sciences ◽

10.1016/j.ijmecsci.2020.105627 ◽

2020 ◽

Vol 179 ◽

pp. 105627 ◽

Cited By ~ 3

Author(s):

Yuguang Cao ◽

Ying Zhen ◽

Ming Song ◽

Haijiao Yi ◽

Fagen Li ◽

...

Keyword(s):

Test Performance ◽

Impact Test ◽

Pipeline Steel ◽

Charpy Impact ◽

Charpy Impact Test ◽

X80 Pipeline Steel

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Test Method for Charpy Impact Test on Thin Specimens of Polyethylene Used in Pressurized Pipes

10.1520/f2231-02r08 ◽

2008 ◽

Author(s):

Keyword(s):

Impact Test ◽

Charpy Impact ◽

Charpy Impact Test ◽

Test Method

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A New Test Method for Determination of Spinnability of Metals

Journal of Engineering for Industry ◽

10.1115/1.3664438 ◽

1961 ◽

Vol 83 (2) ◽

pp. 119-124 ◽

Cited By ~ 35

Author(s):

Richard L. Kegg

Keyword(s):

Test Method ◽

Reduction Of Area ◽

Work Done ◽

Sine Law ◽

Shear Spinning ◽

Qualitative Discussion

A new test method is described whereby the spinnability, i.e., the ability to undergo shear spinning deformation, without fracture, of any material may be determined. Work done to date with this test method indicates that a good nonspinning criterion for estimating spinnability is the tensile reduction of area at fracture. Results of the spinnability test suggest that a feature of this test be adopted in the design of production cone-spinning mandrels. A qualitative discussion of the effects of deviating from the sine law is presented.

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Determination of Ca3(PO4)2 in Bone China by Microwave Digestion-ICP-AES

E3S Web of Conferences ◽

10.1051/e3sconf/202124503088 ◽

2021 ◽

Vol 245 ◽

pp. 03088

Author(s):

Zheng-gen Huang ◽

He-ying Yi ◽

Tao Wang ◽

Lian-ying An ◽

Xiao-bin Zhao

Keyword(s):

Detection Limit ◽

Tricalcium Phosphate ◽

Microwave Digestion ◽

Test Method ◽

National Standard ◽

Good Precision ◽

Test Results ◽

Established Method ◽

Bone China

The establishment of a microwave digestion method with the advantages of simple operation and complete digestion to process samples has shown that, high sensitivity, wide linear dynamic range, good precision, fast analysis speed and many other advantages of ICP-AES technology for rapid determination of tricalcium phosphate in bone china. Through the use of different P2O5 content of phosphate rock and kaolin national standard material configuration standard working solution for matrix matching to eliminate matrix interference, the microwave digestion sample processing condition selection, coexisting ion interference, method precision, accuracy, and detection limit tests were carried out. The results showed that the detection limit of the newly established method for tricalcium phosphate is 0.011mg.L-1; the HCl-HNO3-HF-H2O2 mixed acid decomposition system dissolves the best samples; the interference of the test results through the matrix matching coexisting ion pair is small; The relative standard deviation (RSD) is 1.08%~4.64%, and the recovery rate of standard addition is 92.4%~107.9%. The established method has high accuracy and precision; the bone china samples are analyzed and compared with the conventional digestion national standard method The t test method is used to prove that the two methods are not significantly different from the test results.

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The Effect of Notch Depth on CTOD Values in Fracture Tests of Structural Steel Elements

Polish Maritime Research ◽

10.2478/pomr-2018-0058 ◽

2018 ◽

Vol 25 (2) ◽

pp. 85-91

Author(s):

Jakub Kowalski ◽

Janusz Kozak

Keyword(s):

Brittle Fracture ◽

Test Procedure ◽

Charpy Impact ◽

Steel Structures ◽

Charpy Impact Test ◽

Offshore Structures ◽

The Arctic ◽

Notch Depth ◽

Crack Tip Opening Displacement ◽

Opening Displacement

Abstract In elements of steel structures working at low temperatures, there is a risk of appearance of brittle fracture. This risk is reduced through the use of certified materials having guaranteed strength at a given temperature. A method which is most frequently used to determine brittle fracture toughness is the Charpy impact test, preformed for a given temperature. For offshore structures intended to work in the arctic climate, the certifying institutions more and more often require Crack Tip Opening Displacement (CTOD) tests instead of conventional impact tests, especially for steel and welded joints of more than 40 mm in thickness in the case of high-strength steel, and more than 50 mm for the remaining steels. The geometry of specimens and the test procedure are standardised; however, these standards provide some margin for specimen notch depth. The paper analyses the effect of notch depth difference, within the range permitted by the standards, on the recorded CTOD values of a given material. The analysis was performed via numerical modelling of destruction of specimens with different notch geometries and further verification of the obtained numerical results in laboratory tests. The calculations were carried out at the Academic Computer Centre in Gdansk.

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