The project will help to preserve this potential and will make it available for efforts to improve the safety of existing plants and structures. It will enable the participating laboratories to obtain accreditation according to quality assurance systems, as are specified in EN 45001, ISO 9002, and ISOIIEC Guide 25, for performing these accelerated SCC tests. It will thus help to improve the possibilities for the participating CCE/NIS laboratories to perform contracted SCC investigations for industrial and public clients. Upon successful completion of the project and approval by the Commission the quality assurance tools pertaining to SCC testing which have been developed in the project will become available to other interested parties in both EU member states and CCE/NIS.
The initiation and growth of cracks caused by the combined attack of tensile stresses and chemically aggressive environments, known as stress corrosion cracking, SCC, is one of the most dangerous failure mechanisms in engineering structures. In the damage tolerant approach to SCC small cracks or defects are assumed to be already existent in a structure or component, and laboratory tests on pre-cracked samples are performed in which the loading situation and the service environment are simulated. These tests can help to evaluate critical loads and remaining lifetimes of pre-cracked components in aggressive environments. They also yield information about the efficiency of countermeasures and protection means and provide guidance for the development ant for selection of materials which have a higher resistance to SCC. However, SCC testing according to current standards requires extremely long test times and can lead to non-conservative results. Therefore, the need exists for a rapid test method, provided that this yields reliable data which can be interpreted for long-term cracking problems.
In the proposed project a harmonised accelerated SCC test procedure will be validated and implemented in laboratory SCC testing. This procedure is based on the rising displacement/rising load test method. The work plan includes the development of detailed specifications which are a prerequisite for a successful and reliable application of this test method. The specifications will have the form of a quality handbook which is suitable as a basis for a comprehensive quality assurance system related to this particular test method. Where applicable, the specifications will be based on experience which is currently gathered in another European research project (Programme Standards, Measurements & Testing) and will make use of the long term experience and extensive know how for SCC testing in complex service environments already existent in the participating CCE/NIS laboratories.
In the test programme fracture mechanics based SCC tests using three different test methods and specimens of two different sizes will be performed. The specimens will be manufactured from three steels which are partly of Western standard and partly according to Central/Eastern European standards and which are of practical importance for many industrial applications. Detailed specifications for each step of the test programme and a close collaboration between the partners in the project will ensure that a unified test procedure will be applied in the participating EU and CCE/NIS laboratories.
The participating CCE and NIS laboratories are well known for their excellent expertise in investigating the deleterious influence of corrosive environments, materials ageing and damage of components and structures.
Funding SchemeCSC - Cost-sharing contracts
20097 Milano - San Donato Milanese
166 28 Praha 6
250 68 Rez - Praha