Microstructure Evolution of Environmental Graphitized Hypoeutectoid Free Cutting Steel

Abstract:

Development of low-sulfur and Pb-free free cutting steel is significant because the use of S or Pb free-cutting steel can result in serious pollution. The hypoeutectoid graphitized free cutting steel was proposed. The graphitizaion is difficult due to slow graphitization process, so it is curcial to accelerate the graphitization process. The results show that, through appropriate composition design and technology, the C atom can quickly transform to grahite within 4 hours. The microstructure of the graphitized free cutting steel consists of ferrite, graphite and carbide. Moreover, the grain size of grapite is fine and the distribution is uniform, and the carbide mainly locate the ferrtie grain boundary or in the ferrite. In addition, the nuleation of graphite not only can take place on the second-pahse particles, but also spontaneous nuleation and growth.Key words: free cutting steel, hypoeutectoed steel, graphite, carbide, nucleation

• Periodical: Applied Mechanics and Materials (Volumes 633-634)
• Pages: 192-196
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.633-634.192
• Online since: September 2014
• Authors: Yun Yang Yin*, Fang Fang, Guo Hua Luo, Xiang Yan
• Keywords: Carbide, Free Cutting Steel, Graphite, Hypoeutectoed Steel, Nucleation

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