International round robin test on Master Curve reference temperature evaluation utilizing Miniature C(T) specimen
Yamamoto, Masato*; Onizawa, Kunio
; Yoshimoto, Kentaro*; Ogawa, Takuya*; Mabuchi, Yasuhiro*; Valo, M.*; Lambrecht, M.*; Viehrig, H.-W.*; Miura, Naoki*; Soneda, Naoki*
In order to ensure the robustness of the Master Curve technique, round-robin tests were performed using 0.16 inch-thick Mini-CT specimens by different investigators to see if consistent 
values can be obtained. All the specimens used were machined and pre-cracked by one fabricator from unique Japanese RPV material. Seven institutes participated in this exercise, and obtained valid 
values according to the ASTM E1921 standard. The scatter of 
values obtained was well within the uncertainty range defined in the standard, indicating the robustness of the Mini-CT specimen test technique. Throughout this activity, we could obtain 182 
for a single material. We investigated the statistics of this large database, and found that there is no remarkable difference not only in the 
values but also in the fracture toughness distribution between the Mini-CT specimen and the standard size 1T-C(T) specimen results.