Effect of high magnetic field on alloy carbide precipitation in an Fe-C-Mo alloy

摘要

The effect of a 12-T high magnetic field on molybdenum carbide precipitation during isothermal transformation in an Fe-C-Mo alloy was investigated. Three kinds of alloy carbides (M_2C, M_3C and M_6C) were precipitated when specimens were treated both with and without a 12-T magnetic field. The precipitation of (Fe,Mo)_6C started from the early stage under the high magnetic field, whereas it happened late during conventional treatment. The observed results suggested that the precipitation of (Fe,Mo)_6C was remarkably promoted when specimens were treated in a 12-T magnetic field. In the meantime, the concentration of substitutional solute atoms Fe and Mo in the carbide of (Fe,Mo)6C was greatly influenced by a strong magnetic field. The promotion of specific alloy carbide and the substitutional solute atom concentration change in alloy carbides were attributed to their magnetization differences, which resulted in the change of Gibbs magnetic free energy of the alloy carbides. The investigation of alloy carbide precipitation under high magnetic fields could contribute to a better understanding of phase transformation of alloy carbides and to the heat-treatment and fabrication of high-strength energy materials.