Study on the Ti Micro-Alloyed Ultra-High Strength Steel Produced by Thin Slab Casting and Direct Rolling
New 700MPa hot rolled ultra-high strength steels were successfully developed and produced in large scale by using Ti micro-alloying technology in CSP line. Experimental methods, such as SEM, TEM and chemical phase analysis,were used to study the microstructure and precipitates of the experimental steel. It is shown that the microstructure is composed of quasi-polygonal ferrite grains with average grain sizes ranging from 2.9～3.8μm. Small amount of titanium nitrides with size about several hundreds nanometers and a large fraction of titanium carbides are found in the steels. High dislocation density and the configuration of dislocation tangles can be observed. The major strengthening mechanism of 3mm ultra-high strength steel is grain refinement strengthening, which contributes more than 300MPa to the yield strength. The contribution of precipitation strengthening and solid solution strengthening are calculated as 158MPa and 117MPa,respectively. The contribution of dislocation hardening is estimated to be about 164MPa.
compact strip production (CSP) titanium carbides precipitation hardening grain refinement dislocation hardening
MAO Xin-ping HUO Xiang-dong SUN Xin-jun CHEN Qi-lin
Guangzhou Zhujiang Steel Co.Ltd, Guangzhou 510730, Guangdong, China School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China Institute for Structural Materials, Central Iron and Steel Research Institute, Beijing 100081, China CSP Applying Technology Research Institute of GISE, Guangzhou 510730, Guangdong, China
国际会议
2009年薄板坯连铸连轧国际研讨会(TSCR 2009)(2009 International Symposium on Thin Slab Casting and Rolling)
南京
英文
354-363
2009-05-13（万方平台首次上网日期，不代表论文的发表时间）