Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-27T11:48:37.139Z Has data issue: false hasContentIssue false
  • English
  • Français

Precipitates in Nb and Nb–V Microalloyed X80 Pipeline Steel

Published online by Cambridge University Press:  06 August 2013

Zhongyi Li ,
Delu Liu ,
Jianping Zhang  and
Wenhuai Tian
Zhongyi Li*
Affiliation:
Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China Maanshan Iron & Steel Co. Ltd., Maanshan, Anhui 243000, China
Delu Liu
Affiliation:
Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China
Jianping Zhang
Affiliation:
Maanshan Iron & Steel Co. Ltd., Maanshan, Anhui 243000, China
Wenhuai Tian
Affiliation:
Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China
*
*Corresponding author. E-mail: [email protected]
Get access

Abstract

Precipitates in two X80 pipeline steels were studied by transmission electron microscopy equipped with an energy filtering system. The steels are microalloyed with niobium and niobium–vanadium (Nb–V), respectively, and produced by continuous hot rolling. Besides the precipitates TiN and (Ti, Nb) (C, N), which were 10–100 nm in size, a large number of precipitates smaller than 10 nm distributed in the two steels have been observed. In the Nb–V microalloyed steel, only a few titanium nitrides covered by vanadium compounds on the surface have been observed. It is inferred that the vanadium exists mainly in the matrix as a solid solution element. The fact has been accepted that there was no contribution to the precipitation strengthening of the X80 steel by adding 0.04–0.06% vanadium under the present production process. By contrast, the toughness of the Nb–V steel is deteriorated. Therefore, a better toughness property of the Nb microalloyed X80 results from the optimum microalloying composition design and the suitable accelerating cooling after hot rolling.

Keywords

X80 pipeline steelprecipitateelectron energy filtering microscopymicroalloyed steelNb carbonitrideTi nitrideTEM
Type
Research Article
Information
Microscopy and Microanalysis , Volume 19 , Supplement S5: IUMAS , August 2013 , pp. 62 - 65
Copyright
Copyright © Microscopy Society of America 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Guo, A.M., Zou, D.H., Yi, L.X., Dong, H.X., Li, P.H., Liu, K. & Wu, K.M. (2009). Effects of aging on microstructure and mechanical property of ultralow carbon acicular ferrite steel. Acta Metall Sin 45(4), 390–395.Google Scholar
Perez, M. (2007). Precipitation of niobium carbonitrides in ferrite: Chemical composition measurements and thermodynamic modeling. Phil Mag Lett 87(9), 645–656.10.1080/09500830701427003Google Scholar
Shang, J.X., Zhao, D.L. & Wang, C.Y. (2003). Occupying tendentiousness of niobium in γ-Fe and its effect on grain boundary. Sci China (Ser E) 33(1), 20–24.Google Scholar
Shi, X.L., Zhang, J.P., Zhu, T. & Jiang, H.T. (2008). Production of X80 pipeline steel strips on 2250 hot mill in Masteel. Iron Steel 43(8), 61–64.10.1016/S1006-706X(08)60013-8Google Scholar
Shu, X.L., Wang, C.Y. & Zhao, D.L. (2005). Interaction between dissolved vanadium atom and [100](001) dislocation in iron. J Iron Steel Res 17(5), 48–52.Google Scholar
Turkdogan, E.T. (1989). Causes and effects of nitride and carbonitride precipitation during continuous casting. Iron Steelmaker 16(5), 61–75.Google Scholar
Wang, W. & Gu, H.R. (2010). Influence of coiling temperature on precipitate and property of X80 pipeline steel. J Mater Metall 9(3), 207–210.Google Scholar
Yong, Q.L. (2006a). Theoretical calcualtions of precipitation kinetics of the common second phase in steel. In The Second Phase in Steel Material, pp. 395–396. Beijing: Metallurgical Industry Press.Google Scholar
Yong, Q. (2006b). The role and significance of the second phase in steel material. In The Second Phase in Steel Material, pp. 47–48. Beijing: Metallurgical Industry Press.Google Scholar
Zhu, T., Jiang, H.T., Xu, H.X., Tian, Z.Q. & Li, Z.Y. (2009). Process, microstructure and properties of thick X80 pipeline steel produced by hot continuous rolling. Iron Steel Vanadium Titanium 30(2), 75–79.Google Scholar