Experiments on the magnetostriction properties of the China low activation martensitic steel

•Magnetostriction properties of the CLAM steel in several condition have been investigated.•Along the direction of magnetic field, magnetostriction of the CLAM steel is compressive.•Stress brings significant influence on the magnetostriction properties of the CLAM steel.•The proposed model gives good agreement with experimental results. In this paper, the magnetostriction properties of China Low Activation Martensitic (CLAM) steel, a typical Reduced-activation Ferritic/Martensitic steel developed for fusion reactor application, have been experimentally investigated. With a magnetic field from 0 to 1T and tensile stress from 0 to 130MPa, the correlations of strain-magnetic field intensity in several experimental conditions have been measured. Stress was found giving significant influence on the magnetostriction properties of the CLAM steel. A constitutive model is proposed then for describing the magnetostriction property of the CLAM steel based on the experimental results. The proposed constitutive relation between the magnetic field and the magnetostriction strain gives good description of the observed phenomena and is in good agreement with the experimental results in the middle strength range of applied magnetic field. This work provides a basic constitutive relation for the magneto-mechanical coupling analysis of structures of the CLAM steel in Tokamak fusion reactors.