Jb. Vogt et al., COMBINED EFFECT OF NITROGEN AND SILICON ON LOW-CYCLE FATIGUE OF 12-PERCENT CR MARTENSITIC STAINLESS-STEELS, Zeitschrift fur Metallkunde, 85(2), 1994, pp. 92-99
The low cycle fatigue behaviour of 12% CrMoV type martensitic stainles
s steels has been studied at room temperature taking into account the
chemical composition, especially carbon, nitrogen and silicon. High va
lues of cyclic stress can be obtained in nitrogen plus silicon contain
ing steel. The cyclic plasticity is governed by the state of precipita
tion and by the interactions of dislocations with silicon atoms. TEM a
nalyses show that dislocation arrangements are better formed in the ca
rbon plus silicon alloy (C-Si) and in. the nitrogen alloy (N) than in
the nitrogen plus silicon alloy (N-Si). As a consequence, the surface
plasticity observed in SEM is more difficult to occur in the N-Si allo
y leading to earlier fracture.