European Standard on Small Punch Testing of Metallic Materials

2017 ◽  
Author(s):  
Matthias Bruchhausen ◽  
Tim Austin ◽  
Stefan Holmström ◽  
Eberhard Altstadt ◽  
Petr Dymacek ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Test Methods ◽  
Test Method ◽  
Life Extension ◽  
Tensile Fracture ◽  
Metallic Materials ◽  
Destructive Testing ◽  
Small Punch ◽  
Punch Test

Life extension of aging nuclear power plant components requires knowledge of the properties of the service-exposed materials. For instance, in long term service the tensile and creep properties might decline and the ductile-to-brittle transition temperature (DBTT) might shift towards higher temperatures. Monitoring of structural components in nuclear power plants receives much attention — in particular in the context of lifetime extension of current plants, where the amount of material available for destructive testing is limited. Much effort has therefore been invested in the development of miniature testing techniques that allow characterizing structural materials with small amounts of material. The small punch (SP) test is one of the most widely used of these techniques. It has been developed for nuclear applications but its use is spreading to other industries. Although the SP technique has been used for more than 30 years, there is currently no standard covering its most widely used applications. Within the auspices of ECISS TC 101 “Test methods for steel (other than chemical analysis)” WG 1 is currently developing an EN standard on the “Small Punch Test Method for Metallic Materials”. The standard will address small punch testing for the determination of tensile/fracture properties as well as small punch creep testing. This paper gives an overview of the state-of-the art of the SP tests and describes the scope of the standard under development.

Characterisation of Mechanical Properties by Small Punch Test

2014 ◽  
Vol 606 ◽  
pp. 15-18 ◽  
Author(s):  
Jan Siegl ◽  
Petr Haušild ◽  
Adam Janča ◽  
Radim Kopřiva ◽  
Miloš Kytka
Keyword(s):  
Mechanical Properties ◽  
Coming Out ◽  
Nuclear Power ◽  
Power Plants ◽  
Fracture Toughness Test ◽  
Small Punch Test ◽  
Charpy Test ◽  
Small Punch ◽  
Punch Test

The specific desired properties for structures and components working in critical environments (e.g. different structure parts of power plants) require current information about degradation processes coming out in materials. Obtaining of this information by the help of the classical tests of mechanical properties (tensile test, Charpy test, fracture toughness test, creep test etc.) is very limited namely in the case of nuclear power plants pressure vessel. Hence, the new innovative techniques based on miniaturized specimens have been developed for evaluation of mechanical properties and their changes. One of very promising techniques is Small Punch Test. Present paper deals with characterization of three different steels (15Ch2MFA, 10GN2MFA with different heat treatment and steel O8Ch18NT10 with various degree of deformation).

Evaluation of Mechanical Properties of the Reactor Pressure Vessel Materials Changes by Small Punch Test Application

2013 ◽  
Author(s):  
Jana Petzová ◽  
Martin Březina ◽  
Ľudovít Kupča
Keyword(s):  
Mechanical Properties ◽  
Pressure Vessel ◽  
Nuclear Power ◽  
Power Plants ◽  
Mechanical Tests ◽  
Reactor Pressure Vessel ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test ◽  
Reactor Pressure

The reactor pressure vessel (RPV) is the most important component of nuclear power plants. RPV steel near the reactor core is subject of irradiation degradation due to the fast neutron flux. Irradiation processes are rather complex but after all the damage of the steel crystal lattice lead to the changes of RPV mechanical properties as well as the shift of the transition temperature to higher values. Hence, monitoring of the RPV material irradiation changes must be proved during the all nuclear power plant (NPP) operation. The new surveillance specimen programs (SSP) at all Slovak NPPs reactors included, among the standard mechanical tests, also new types of evaluation mechanical properties due to method Small Punch Test (SPT).

Evaluation of Thermal Aging Embrittlement in Main Coolant Pipe Steel by Small Punch Test

2010 ◽  
Author(s):  
Fei Xue ◽  
Weiwei Yu ◽  
Xiao Chen ◽  
Yan Liu ◽  
Zhenhao Shi ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Nuclear Power ◽  
Power Plants ◽  
Aging Effect ◽  
Initial Increase ◽  
Pipe Material ◽  
Test Results ◽  
Small Punch ◽  
Punch Test ◽  
The Difference

To evaluate the thermal aging embrittlement in the main coolant pipe material of nuclear power plants, a series of small punch testes at room temperature were performed on Z3CN20.09M duplex stainless steel aged at 400°C for up to 10000 hours, and then the fractured specimens were examined by the SEM. The test results indicate that the aging heat treatment led to a slight increase of the strength, and caused an initial increase on the small punch energy followed by continual decrease when the aging time extends 1000 hours. Besides, the fracture mode of specimens aged at 400°C for different time exhibited some discrepancy, but the difference is not clearly to reflect the thermal aging effect on the material.

Small Punch Testing - The Transition from a Code of Practice to a European Testing Standard

2017 ◽  
Vol 734 ◽  
pp. 3-22 ◽  
Author(s):  
Karel Matocha ◽  
Roger Hurst
Keyword(s):  
Mechanical Properties ◽  
Test Method ◽  
Metallic Materials ◽  
Small Punch Test ◽  
Test Technique ◽  
Small Punch ◽  
Code Of Practice ◽  
Punch Test ◽  
Early Results ◽  
Miniature Testing

The development and practical use of the Small Punch test technique for the evaluation of mechanical properties of metallic materials in Europe resulted in the publication of the CEN document CWA 15627 Small Punch Test Method for Metallic Materials in 2007. The evaluation of the actual mechanical properties of metallic materials from the results of such tests according to CWA 15627 were presented at the first three International conferences SSTT "Determination of Mechanical Properties by Small Punch and other Miniature Testing Techniques" held in Ostrava (2010, 2012) and Castle Seggau in Austria (2014). In the present paper the motivation and the steps taken to lead to the setting up of a working group and programme facilitating the transformation of CWA 15627 Small Punch Test Method for Metallic Materials into an EN standard are summarized along with early results of the programme.

Life Extension of Nuclear Power Plants: World Situation and the USA Case

2010 ◽  
pp. 50-56 ◽  
Author(s):  
Pablo T. León ◽  
Loreto Cuesta ◽  
Eduardo Serra ◽  
Luis Yagüe
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Life Extension ◽  
The Usa

Application of Small Punch Test to Evaluate Tensile Properties of SA213T22 Grade Boiler Steel

2015 ◽  
Vol 830-831 ◽  
pp. 191-194
Author(s):  
M. Venkateswara Rao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Tensile Properties ◽  
Test Methods ◽  
Uniaxial Tensile ◽  
Test Results ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test ◽  
Aging Phenomena

Conventional tensile test methods are used for service exposed high temperature boiler tubes to evaluate the deterioration in mechanical properties such as tensile strength, yield strength and percentage elongation. The mechanical properties are required to be evaluated periodically as the boiler components undergo material degradation due to aging phenomena. The aging phenomena occurs due to continuous exposure of tubes to high temperature & pressure steam prevailing inside the tubes and high temperature exposure to corrosive combustible gases from the external surfaces within the boiler.A recent developed new technique called small punch testing has been used to evaluate the tensile properties of SA 213T22 grade steel predominantly exists in super-heater and re-heater sections of boiler. The small punch tests have been carried out on the miniature disk shaped specimens of diameter of 8.0 mm and 0.5 mm thickness extracted from both the new and service exposed tubes. Conventional uniaxial tensile tests on standard specimens from the same tube material have also been performed for comparison. The service exposed tubes showed considerable loss in mechanical properties in both the conventional and small punch test results. Correlations of tensile properties have been obtained based on the comparative analysis of both small punch and uniaxial tensile test results. Further, the study showed that an appropriate empirical relation could be generated for new and service exposed materials between both the techniques. Conventional test methods require large quantity of material removal for test samples from in-service components whereas small punch test method needs only a miniature sample extraction. This small punch test technique could also be extended to evaluate the thicker section boiler components such as pipelines and headers in the boiler as a part of remaining life assessment study. Also this technique could be a useful tool to any metallic component where large quantity of sample removal may be difficult or may not be feasible.

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