Abstract The morphology, size, distribution and types of precipitate particles were studied by using OM, SEM, TEM, EDS and SAEDP for Ti-Mo low-carbon ferrite matrix micro-alloy steel with four different titanium contents. Experimental results indicated that there were two kinds of particles with obvious different sizes in ferrite matrix, one was nanometer sized particles, which were smaller than 10 nm, the composition of these particles was compound carbonitride of Ti and Mo. These particles precipitated in chains or dispersed in the interior of grains. Dislocation nodes and the dislocation network were preferential nucleation sites for these particles. Another kind of particles was titanium carbonitride larger particles with a “cap” and few in number in ferrite matrix. Their size was about 200 to 300 nm and morphology was square. Tensile experimental results at room temperature and high temperatures showed that ferrite matrix micro-alloy steel with nanometer sized had good mechanical properties. No.4 steel had good performance at 600 ℃ with a yield strength of about\linebreak 300 MPa.
[1] Cao J C. PhD Thesis, Kunming University of Science and Technology, 2006
(曹建春. 昆明理工大学博士学位论文, 2006)
[2] Gladman T. Mater Sci Technol, 1999; 15: 30
[3] Yong Q L. Secondary Phase in Steel. Beijing: Metallurgical Industry Press, 2006: 15
(雍岐龙. 钢铁材料中的第二相. 北京: 冶金工业出版社, 2006: 15)
[4] Andrade H L, Akben M G, Jonas J J. Metall Trans, 1983; 14A: 1967
[5] Lee W B, Hong S G, Park C G, et al. Metall Mater Trans, 2002; 33A: 1689
[6] Lee W B, Hong S G, Park C G. Scr Mater, 2000; 43: 319
[7] Yang S W, He X L, Chen M D. Mater Sci Technol, 1994; 12(2): 49
(杨善武, 贺信莱, 陈梦滴. 材料科学与工程, 1994; 12(2): 49)
[8] Wang Z D, Qu J B, Liu X H. Acta Metall Sin, 2000; 36: 618
(王昭东, 曲锦波, 刘相华. 金属学报, 2000; 36: 618)
[9] He X L, Shang C J, Yang S W. High Performance Low Carbon Bainite Steel/Ingredients, Process, Microstructure, Properties and Application. Beijing: Metallurgical Industry Press, 2008: 152
