supported by the National Basic Research Program of China(No.2009CB623704);the National Natural Science Foundation of China(Nos.51071064 and 51171063);the Nature Science Foundation of Hunan Province(Grant No. 09JJ6002);Instrumental Innovation Foundation of Hunan Province(No.2011TT1003);the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
The coarsened grain boundaries (GBs) with vein-like morphology frequently appear in the nitrogen diffusion layer of nitrocarburized carbon steels. The electron probe X-ray microanalysis shows that such vein-like GBs...