Abstract: Reduced activation martensitic steel wires were normalized at 1000-1100 ℃ for 60 min and then tempered at 790 ℃ for 90 min, and the effect of normalizing temperature on microstructure and mechanical properties of the reduced activation martensitic steel wires was investigated. The results show that after normalizing, the microstructure of the reduced activation martensitic steel is transformed from granular pearlite to lath martensite, and the carbide particles are partially dissolved in martensite matrix. With the increase of normalizing temperature, more carbide particles can be dissolved into the matrix and completely dissolved at 1100 ℃, and the grain size of prior austenitic increases (from 7.4 μm at 1000 ℃ to 34.9 μm at 1100 ℃). After tempering, the lath spacing of martensitic widens, and the high-density dislocations are rapidly recovered and disappeared, while precipitated phases are precipitated, spheroidized and grow up along grain boundary and inside, the M₂₃C₆(M is dominated by Cr) phases are short rod shape, which are distributed on the grain boundary, while the MX (M is dominated by Ta) phases are elliptic shape, which are mainly distributed in the lath martensitic. The reduced activation martensitic steel has the best comprehensive mechanical properties after normalizing at 1000 ℃ for 60 min and tempering at 790 ℃ for 90 min, with tensile strength of 745.7 MPa and elongation of 18.9%.

Key words: reduced activation martensitic steel, normalizing temperature, microstructure, mechanical properties, precipitated phase