抄録
The effects of carbon on reversion behavior of metastable austenitic stainless steel were investigated using a 16.2% Cr- 8.8% Ni- 0.11% C steel by means of transmission electron microscopy and magnetic analysis. The steel used almost transforms to lath martensite (α') from austenite (γ) by 90% cold rolling.
The results are as follows:
(1) The steel completely reverses on 923 K-10 s annealing. However, isothermal α' is produced on subsequent aging at room temperature (290 K) in case of more than 0.1 ks in 923 K isothermal annealing, and also at 900 K and above in 0.6 ks isochronal annealing.
(2) In case of 923 K annealing, carbide precipitation occurred in preference to reversion. The carbide tends to retard a martensitic reversion and accelerate a diffusional reversion inversely.
(3) The grain size of γ reversed by a diffusional reversion at 923 K annealing is 0.2 μm dia. The carbide is very effective for refining grain by reversion.
