Nitrogen diffusion through cementite layers

作者：Nikolussi Marc; Leineweber Andreas^*; Mittemeijer Eric Jan

来源：Philosophical Magazine, 2010, 90(9): 1105-1122.

DOI：10.1080/14786430903292365

• cementite
• nitrogen diffusion
• activation energy
• nitrocarburising
• nitriding

Massive cementite layers with a time-dependent thickness were grown on ferrite substrates by nitrocarburising in a dedicated NH(3)/H(2)/CO/N(2)-containing gas atmosphere at 783 K, 823 K and 843 K. Nitrogen diffusion through the cementite layer into the ferrite substrate took place in conjunction with growth of the cementite layer; a significant, i.e. measurable, solubility of nitrogen in cementite was not observed. The nitrogen concentration-depth profiles in the substrate, underneath the growing cementite layer, were quantitatively determined using a calibrated microhardness measurement technique. The nitrogen concentration-depth profiles were simulated on the basis of a model using an implicit finite-difference method. The simulation yielded values for the diffusivity of nitrogen through cementite, including its activation energy.

• 出版日期2010
• 单位中国科学院金属研究所