Diffusive transport parameters of deuterium through China reduced activation ferritic-martensitic steels

Abstract

Reduced Activation Ferritic/Martensitic (RAFM) steels have been considered as the most promising candidate structure materials for a fusion reactor. In the recent decades, two new types of RAFM steels, called China Low Activation Martensitic (CLAM) steel and China Low-activation Ferritic (CLF-1) steel, have been developed. The gas evolution permeation technique has been used to investigate diffusive transport parameters of deuterium through CLAM and CLF-1 over the temperature range 623 ∼ 873 K at deuterium pressure of 105 Pa. The resultant transport parameters are: Φ (mol. m−1 s−1 Pa−1/2) = 5.40 × 10−8 exp (−46.8 (kJ. mol−1)/RT), D(m2 s−1) = 3.81 × 10−7 exp(−24.0(kJ. mol−1)/RT) and S (mol. m−3 Pa−1/2) = 1.42 × 10−1 exp(−22.8(kJ. mol−1)/RT) for CLAM; while Φ(mol m−1 s−1 Pa−1/2) = 1.76 × 10−8 exp(−43.9(kJ. mol−1)/RT), D(m2. s−1) = 1.02 × 10−7 exp(−16.9(kJ. mol−1)/RT) and S(mol. m−1 Pa−1/2) = 1.73 × 10−1 exp(−27.0(kJ. mol−1) /RT) for CLF-1. The results show that CLAM is more permeable than CLF-1, thus it is easier for hydrogen isotopes to transport and be removed.