Influence of cyclic martensitic transformations on stabilization of reverted austenite in N32 and G18C2 alloys
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Abstract
A completeness of the direct γ-α- and γ-ε- martensitic transformations in N32 and G18C2 alloys respectively was investigated in this paper depending on the number of the cycles of γ-α-γ- and γ-ε-γ- transformations. It was shown that in N30, N32 and N28T2U2 alloys in the conditions of alloys heating within the limits of α-γ- reverse transformation with the speed of (50-70) deg/sec the amount of martensitic α-phase has decreased by only 8%. As for G18C2 alloy after a hundred of γ-ε-γ- cycles the amount of martensitic ε-phase was 95%. These laws of completeness changing under the conditions of the direct γ-α- and γ-ε- transformations allowed achieving a high degree of phase hardening in iron and ferromanganese alloys.
As a result of rising of the degree of phase hardening by increasing the number of γ-ε-γ- transformations the stabilization of the reverted austenite was not observed, as it was in the case of a number of other iron alloys.
Thus, the ability of carbon-free iron and ferromanganese alloys for carrying of cyclic martensitic transformations with high completeness under the direct γ-α- and γ-ε- transformations makes it possible to achieve a high degree of phase hardening and therefore to investigate the effect of defects accumulation on the characteristics of the diffusion processes in crystal structure.
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References
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