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One of the tasks within the framework of the EU “RESQUE”- project was to determine the lowest acceptable insert length for reconstituted Charpy V impact (Cv) and pre-cracked Charpy V (PC Cv) specimens. In order to obtain an optimized insert length, Cv impact specimens with three insert lengths ranging from 10 to 20 mm and fracture toughness PC Cv specimens with two different insert lengths of a reference material were manufactured by stud-welding or electron-beam welding and tested under various test conditions. Cv tests on reconstituted specimens exhibited the normal scatter in Charpy energies and that there was no significant influence of the insert length on the transition temperatures. However, the 10 mm insert caused a reduction in the upper shelf energy of 10–15%. The fracture toughness tests carried out in the transition regime showed that the 10 mm insert resulted in a lower estimate (non-conservative) of T0 compared with the values measured on 12mm insert and baseline specimens. It is therefore recommended that at least 12 mm long inserts should be used for fracture toughness testing in the transition region. In the ductile region a trend to lower initiation toughness values at higher temperatures was observed. To avoid this, 20 mm long inserts should be used for J-Δa curves at higher temperatures.

This paper summarizes the experience of the RESQUE project. The final objective of the project was the development of a set of 'Recommendations for Reconstitution of Non-Irradiated and Irradiated Charpy-size Specimens,' based on the systematic analysis of the experimental data from the program and on the collective reconstitution experience available in different laboratories within Europe. The paper reviews the general information from RESQUE and summarizes the conclusions. Specific details are given in other contributions to this Symposium.

This paper continues reporting on the EU-sponsored research project RESQUE. First detailed checks with different ways to instrument reconstitution inserts were performed and thin silver soldered thermocouples were chosen to be used in the project. Temperature transients in welded inserts were measured in detail in order to compare the properties of six different reconstitution systems. The measured temperature transients were repeatable and relatively consistent. Within approximately 4 mm of the near weld seam volume a typical material irradiation temperature was exceeded for a short time. This value was nearly the same by all devices. Validation tests with original and reconstituted specimens were performed. No indication of material annealing in reconstitution, i.e. a trend towards lower transition temperatures, was noticed. As compared to the requirements of ASTM E1253-88, the applied insert lengths were too short. Still original data was repeated with reconstituted specimens, which is an indication that the standard is conservative.