The reproducibility of corrosion testing in supercritical water-Results of a second international interlaboratory comparison exercise

Supercritical water-cooled reactor candidate materials are typically corrosion-resistant alloys whose mass changes in supercritical water fluctuate around zero. A previous interlaboratory corrosion experiment exercise revealed large scatter in mass change results between laboratories. Here, we reduced systemic differences between laboratories by unilateral preparation of coupons and unilateral chemical cleaning. Type 310S stainless steel and Alloy 800HT test coupons were exposed for 10 0 0 h to 550 degrees C, 25 MPa, deaerated water. Average mass loss for 310S and 800HT was 38 +/- 26 and 51 +/- 31 mg/dm(2), respectively. Differences in mass transfer, galvanic and local corrosion, and average coupon temperature may explain the poor reproducibility. (c) 2022 Published by Elsevier B.V.

Automated summary

This study reduced systemic differences between laboratories by unilateral preparation of coupons and unilateral chemical cleaning. The results showed significant mass loss of candidate materials for supercritical water-cooled reactors under experimental conditions, possibly due to factors such as mass transfer, galvanic and local corrosion.