caa a22 4500 463227719 CHVBK 20180405153232.0 cr unu---uuuuu 170326e20071201xx s 000 0 eng 10.1007/s10853-007-2000-4 doi (NATIONALLICENCE)springer-10.1007/s10853-007-2000-4 Precipitation of MC phase and precipitation strengthening in hot rolled Nb-Mo and Nb-Ti steels [Elektronische Daten] [Jianchun Cao, Qilong Yong, Qingyou Liu, Xinjun Sun] Hot rolled Nb-Mo steel of yield strength 600MPa and Nb-Ti steel of yield strength 525MPa with polygonal and acicular ferrite microstructure have been developed. Using physicochemical phase analysis, XRD, TEM and EDS, the distribution, morphology, composition, crystal structure and particle size of precipitates were observed and identified in these steels. The results revealed that the steels containing both Nb and Mo exhibited fine and uniformly distributed MC-type carbides, while the carbides were coarse and sparsely distributed in the steels containing Nb and Ti. The physicochemical phase analysis showed MC-type carbides contain both Nb and Mo, and the ratio of Mo/Nb was 0.41. Meanwhile, the mass% of the fine particles (<10nm in size) of Nb-Mo steel was 58.4%, and higher than that of Nb-Ti steel with 30.0%. Therefore, the results of strengthening mechanisms analysis showed the higher strength of Nb-Mo steel than that of Nb-Ti steel is attributed to its relatively more prominent precipitation strengthening effect. The yield strength increments from precipitation hardening of Nb-Mo steel attained 182.7MPa and higher than that of Nb-Ti steel. Springer Science+Business Media, LLC, 2007 Cao Jianchun Department of Materials and Metallurgy Engineering, Kunming University of Science & Technology, 650093, Kunming, Yunnan, China aut Yong Qilong Institute of Structural Materials, Central Iron & Steel Research Institute, 100081, Beijing, China aut Liu Qingyou Institute of Structural Materials, Central Iron & Steel Research Institute, 100081, Beijing, China aut Sun Xinjun Institute of Structural Materials, Central Iron & Steel Research Institute, 100081, Beijing, China aut Journal of Materials Science Springer US; http://www.springer-ny.com 42/24(2007-12-01), 10080-10084 0022-2461 42:24<10080 2007 42 10853 https://doi.org/10.1007/s10853-007-2000-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-007-2000-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cao Jianchun Department of Materials and Metallurgy Engineering, Kunming University of Science & Technology, 650093, Kunming, Yunnan, China aut NATIONALLICENCE 700 1- Yong Qilong Institute of Structural Materials, Central Iron & Steel Research Institute, 100081, Beijing, China aut NATIONALLICENCE 700 1- Liu Qingyou Institute of Structural Materials, Central Iron & Steel Research Institute, 100081, Beijing, China aut NATIONALLICENCE 700 1- Sun Xinjun Institute of Structural Materials, Central Iron & Steel Research Institute, 100081, Beijing, China aut NATIONALLICENCE 773 0- Journal of Materials Science Springer US; http://www.springer-ny.com 42/24(2007-12-01), 10080-10084 0022-2461 42:24<10080 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer