Environmentally assisted fatigue data from the INCEFA-PlUS project

The European project INCEFA-PLUS characterises environmentally assisted fatigue in light water reactor conditions. The project aims at developing a new procedure to assess environmentally assisted fatigue damage susceptibility in nuclear power plant components. The basis for the development of a new fatigue assessment procedure is a major test campaign carried out in eleven different laboratories across Europe which will deliver approximately 200 fatigue tests. The test campaign is based on a common test matrix that was optimized by means of the Design of Experiments method. The initial focus of the project is on the effects and interactions between the factors strain range, environment (air and light water reactor environment), surface finish, hold time, and mean strain. Whereas the bulk of the test program is carried out on a single heat of 304L austentic steel, some tests on different heats of 304L or other austenitic steels allow studying the influence of material variability. To guarantee the quality of the data, the tests are performed according to commonly agreed specifications based on ISO 12106 and each test is validated by a group of experts from within the project. The paper presents the test procedures, provides an overview of the data that has been acquired so far, and gives an outlook on the tests that will be carried out during the final stage of the project.