QUASI-STATIC LOADING RATE EFFECT ON THE MASTER CURVE REFERENCE TEMPERATURE OF FERRITIC STEELS AND IMPLICATIONS

摘要

It has long been recognized that there is a considerable difference between the dynamic and quasi-static fracture toughness reference temperature. However, it has not been clear whether this loading rate effect extends into the quasi-static loading regime. The current fracture toughness reference temperature test standard for ferritic steels (ASTM E1921) specifies an allowable quasi-static loading rate range spanning 100 fold. Recently obtained data from the IAEA JRQ material suggests that the same loading rate effect extends throughout this allowable quasi-static loading rate range. The loading rate effect could amount to a difference in the measured reference temperature of 23℃ (41℉) between the extremes of the specified range. This paper presents the data demonstrating this effect, examines different ways of calculating the loading rate, suggests changes to related to the test standard, and discusses the use of applying the loading rate effect on reference temperature.