Research and development on the China low activation martensitic steel (CLAM)

Abstract Chinese low activation martensitic steel (CLAM) has been designed with improved composition, and its performance, such as tensile properties, ductile–brittle transition temperature (DBTT 41J ), creep and thermal physical properties, has been determined. The interaction experiments between CLAM and plasma were carried out in the HT-7 tokamak facility and the activities, afterheat and gamma dose rate for CLAM as a function of cooling time (CT) were calculated to obtain the required control levels of impurities in CLAM. The insulator coatings on CLAM steel prepared by the CVD process at 700 °C and 740 °C have pure Al 2 O 3 and Al 2 O 3 with an oxygen deficiency layer on surface about 1 μm thick. The electrical resistivity of the coating reaches about 10 4  Ωm 2 on the surface.