Elinvar maraging steels with high elastic limit

Abstract

1. Good elastic and elinvar properties (low TCF) of steels based on N23K9M5T containing 22–24% Ni and 1.0–1.8% Ti are attained by heating them to temperatures of the biphase (α+γ)-region. 2. Preliminary cold forming (rolling) with e=30–50% and subsequent aging lead to a considerable increase of the elastic limit (Δσ0.005=300–400 N/mm2) but have practically no effect on the TCF. 3. Steels N23K9M5T1 (1.1% Ti) and N24K9M5T2 (1.8% Ti) have an optimal complex of elastic and elinvar properties after deformation with e=50%, cold treatment at −196°C, and aging at 560–575°C 3 h: σ0.005=1400–1450 N/mm2, TCF20–100=±(10–20)·10−6 l/deg.