1992 Volume 78 Issue 5 Pages 806-813
In order to obtain the basic information for developing high hardness non-magnetic steel, the effects of alloying elements and heat treatment on various hardening mechanisms and magnetic permiability were investigated in 18Mn-5Cr-2Ni-C steels. Large work hardening was not always found in steels which were presumed to have low stacking fault energy. This fact could be qualitatively explained by the relationship between the formation mechanism of deformation twin and pre-existing dislocation configuration, and by the effect of SFE on a breaking down of Interstitial-Substitutional complexes. Vanadium increased hardness effectively through precipitation of fine V4C3 carbide, whereas it reduced an amount of ε martensite produced by cold working. Silicon addition enhanced the precipitation of V4C3 and strain aging. The increase in hardness could be kept even after the reversed transformation of ε martensite. In high C steels, per meability was increased when M3C carbide precipitated. Through suitable heat treatment, a steel with high hardness around HV 650 and very low permeability could be obtained.
