Development of small punch test for EAC evaluation

We are developing a Small-Punch SCC testing apparatus with an in-situ observation system applied to high temperature water and high pressure. This new testing apparatus is used to evaluate the Environmentally Assisted Cracking effect. A constant loading rate was carried out with different values of speed, of water flow rate and different polishing of the sample. In BWR (Boiling Water Reactor) conditions (9MPa and 288 degrees C) it was found that the loading rate, water flow rate and surface preparation of the sample have some influence if the test is performed during a short time (maximum 4 days). After the test, by SEM observation, studying the secondary microcracks, it is possible to find all the sequences of EAC process. The in-situ observation system permits to study the strain of the sample during the test.