Can we change steel properties by application of magnetic field while quenching?

Question

Austenite is non magnetic while $\alpha$-ferrite and pearlite are magnetic. (Magnetic properties of pearlite vary as a function of carbon content)

If a strong magnetic field is applied in a particular direction while the steel is being quenched (rather, austenite is being quenched!), would the grain structure change? Is it possible to get superior grain structure and hence tougher steel by application of cyclic magnetic field?

My speculation is that, at the eutectoid point while quenching the steel, as low carbon zone of pearlite has more permeability, that zone should align itself to the strong magnetic field by pushing the carbon in orthogonal direction, so grain boundaries should take a different shape.

Will it actually happen?

Answer 1

This will at least depend on the:

• Rate of Cooling
• Magnetic field strength
• Exact composition

The magnetic field will alter the microstructure as you can read in, for example,

• Yudong Zhang, Nathalie Gey, Changshu He, Xiang Zhao, Liang Zuo, Claude Esling, High temperature tempering behaviors in a structural steel under high magnetic field, Acta Materialia, Volume 52, Issue 12, 12 July 2004, Pages 3467-3474, ISSN 1359-6454, http://dx.doi.org/10.1016/j.actamat.2004.03.044.
• G.M. Ludtka, R.A. Jaramillo, R.A. Kisner, D.M. Nicholson, J.B. Wilgen, G. Mackiewicz-Ludtka, P.N. Kalu, In situ evidence of enhanced transformation kinetics in a medium carbon steel due to a high magnetic field, Scripta Materialia, Volume 51, Issue 2, July 2004, Pages 171-174, ISSN 1359-6462, http://dx.doi.org/10.1016/j.scriptamat.2004.03.029. (http://www.sciencedirect.com/science/article/pii/S1359646204001770)

For me, it is behind a paywall. But as you can read in the abstract, 30 Tesla will result in, for example, more ferrite. The other paper reveals that for a hyper eutectoid steel, you will have particle like cementite.

I am not aware of any models with which you can make predictions about tensile strength and so on. But, for the question Can we change steel properties by application of magnetic field while quenching?, it is a clear yes. A more complete lookup in the literature would be the next step for models and experiments for a more specific case.