Mechanical Properties of the Heat Affected Zone of an X100 Grade Pipeline Steel


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The microstructure and mechanical properties of an X100 grade pipeline steel were investigated by the thermal simulation tests performed on a Gleeble-3500 thermal simulator. The results show that the steel has excellent weldability. Even if the weld heat input gets 40 kJ mm-1, the low impact toughness energy in welding coarse grain heat affected zone (CGHAZ) is still higher than 200 J. Yet, an embrittlement zone emerges in inter-critical HAZ (ICHAZ) at the peak temperature of 750 °C, and the lowest strength appears in fine grained HAZ (FGHAZ) at the peak temperature of 950 °C. Moreover, the strength and toughness decrease with the increase of heat input.



Materials Science Forum (Volumes 773-774)

Edited by:

A. Kiet Tieu, Hongtao Zhu and Qiang Zhu




G. Y. Qiao et al., "Mechanical Properties of the Heat Affected Zone of an X100 Grade Pipeline Steel", Materials Science Forum, Vols. 773-774, pp. 795-802, 2014

Online since:

November 2013




[1] H. sahi, T. Hara, E Tsuru, et al., Development of Ultra High-Strength Linepipe X120, Nippon Steel Technical Report, Japan, 90 (2004) 70-75.

[2] H. G. Hillenbrand, C. Kalwa, Production and Service Behavior of High Strength Large Diameter Pipes. Proceedins of International Conference on the Application and Evaluation of High-Grade Linepipes in Hostile Environments, Yokohama, Japan, Scientific Surveys Ltd, 2002, pp.203-215.

[3] S. Moeinifar, A.H. Kokabi, H.R. Madaah Hosseini, Role of tandem submerged arc welding thermal cycles on properties of the heat affected zone in X80 microalloyed pipe line steel, J. Mater. Process. Tech. 211 (2011) 368-375.


[4] S. Shanmugam, R. D. K. Misra, J. Hartmann and S. G. Jansto, Microstructure of high strength niobium-containing pipeline steel, Mat. Sci. Eng. A, 441 (2006) 215-229.


[5] D. Porter, A. Laukkanen, P. Nevasmaab, Performance of TMCP steel with respect to mechanical properties after cold forming and post-forming heat treatment, Int. J. Press. Ves. Pip. 8 (2004) 867-877.


[6] K. P. Kolhe, C. K. Datta, Prediction of microstructure and mechanical properties of multipass SAW, J. mate. Process. Tech. 197 (2008) 241-249.

[7] G. Krauss and S. W. Thompson, Ferrite microstructures in continuously cooled low and ultralow carbon steels, ISIJ Inter. 35 (1995) 937-945.


[8] G. -y. Qiao, F. -r. Xiao, X. -b. Zhang and Y. -b. Cao, B. Liao, Effects of contents of Nb and C on hot deformation behaviors of high Nb X80 pipeline steels, Trans. Nonferrous Met. Soc. China, 19 (2009) 1395-1399.


[9] M. -C. Zhao, K. Yang, Y. -Y. Shan, Comparison on strength and toughness behaviors of microalloyed pipeline steels with acicular ferrite and ultrafine ferrite, Mater. Lett. 57 (2003) 1496-1500.


[10] C. -m. Wang, X. -f. Wu, J. Liu and N. -a Xu, Transmission electron microscopy of martensite/austenite islands in pipeline steel X70, Mat. Sci. Eng. A, 438-440 (2006) 267-271.


[11] Y. W. Shia, Z. X. Han, Effect of weld thermal cycle on microstructure and fracture toughness of simulated heat-affected zone for a 800MPa grade high strength low alloy steel, J. Mater. Process. Tech. 207 (2008) 30-39.