Influence of composition of surface and grain boundaries on mechanical and magnetic properties of Fe-Ni base steels

Methods of X-ray electron spectroscopy and secondary ion mass-spectrometry were used to study the composition and chemical states of elements as at the free surface so at the surfaces of brittle and mixed (ductile-brittle) fracture in a number of high alloy steels depending on heat treatments. It is revealed that the correlation exists between temperature dependence of surface chemical composition on the one hand and mechanical (strength) and magnetic (coercive force) properties on the other. A conclusion is made that there is a threshold concentration of the element in the alloy below which no segregation of this element at the surface is observed. Experiments were carried out using specimens of the following steels: N18, N18T3, N18K9M5T, 03Kh20N45M4BCh, 04Kh16N11M3T