Magnetic properties and microstructure of AISI 1000 series carbon steels

Abstract

The magnetic properties of a number of specimens of AISI 1000 series plain carbon steels have been measured as functions of chemical composition, microstructure and heat treatment. The results showed that for a given morphology of the carbides the magnetic properties such as coercivity and permeability varied smoothly as a function of carbon content. Coercivity increased with carbon content by 2.0 Oe for every 0.1 wt.% carbon added at low carbon contents while initial permeability decreased by 57% on the addition of 0.2 wt.% carbon in the form of lamellar carbides (pearlite), but by only 21% when those carbides were in the form of spheroidised particles. In all cases the spheroidised specimens were found to be magnetically softer than the lamellar specimens and the difference increased with the amount of carbon present. Grain size did not seem to affect the magnetic properties significantly above a carbon content of 0.2 wt.%, although it was known that grain size is a significant factor in determining magnetic properties in iron alloys with lower carbon content.

Sensitivity of Conventional and Non-destructive Characterization Techniques to Recovery and Recrystallization

“…When carbon and nitrogen dissolve in a-iron, they tend to enter the lattice interstitially and produce a local lattice straining, which could contribute to a degradation of the magnetic properties, which would be reflected as an increase of the coercive field. However, some experimental results obtained in carbon steels 34) showed that the amount of carbon in solid solution in a-iron was not a very significant factor affecting structure-sensitive magnetic properties. Additionally, it is expected that in cold rolled steels these elements segregate to dislocations, instead of entering interstitially into the ferrite matrix.…”

Effect of Microstructural Features on Mechanical and Magnetic Properties of Austempered High-silicon Ductile Irons

“…This is consistent with the results of Jiles et al, who found that the coercivity generally increased with increasing hardness in a plain carbon steel. 26) In the GJS 600-10 samples, on the other hand, both the coercivity and the mean ferritic cell size increased as the austempering temperature increased (Fig. 14(b)), which is similar to the variation of remanence (Fig.…”

Correlation of Magnetic Barkhausen Emission Profile with Strength of Thermally Degraded 2.25Chromium–1Molybdenum Steel

“…In our previous reports on microstructural characterization of these specimens, 1,2) major microstructural changes due to isothermal exposure to 630 C were revealed to be the depletion of solid solution atoms from the matrix, and the carbide-related changes such as coarsening, spheroidization and precipitation of stable carbides. Considering that the solute atoms are not effective in pinning magnetic domains, 15) the evolution of P PEAK shown in Fig. 4 can be explained in terms of carbides.…”