Hostname: page-component-8448b6f56d-t5pn6 Total loading time: 0 Render date: 2024-04-24T12:00:43.800Z Has data issue: false hasContentIssue false
  • English
  • Français

Investigation on the weakest zone in toughness of 9Cr/NiCrMoV dissimilar welded joint and its enhancement

Published online by Cambridge University Press:  13 June 2017

Xia Liu ,
Zhipeng Cai ,
Xionglin Deng  and
Fenggui Lu
Xia Liu
Affiliation:
Department of Mechanical Engineering, Tsinghua University, Beijing 100084, People’s Republic of China
Zhipeng Cai*
Affiliation:
Department of Mechanical Engineering, Tsinghua University, Beijing 100084, People’s Republic of China
Xionglin Deng
Affiliation:
School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
Fenggui Lu*
Affiliation:
School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
*
a)Address all correspondence to these authors. e-mail: czpdme@mail.tsinghua.edu.cn
b)e-mail: Lfg119@sjtu.edu.cn
Get access

Abstract

The impact toughness and related microstructure of the dissimilar 9Cr/NiCrMoV welded joint fabricated by narrow-gap submerged arc welding were systematically investigated in the paper. Results indicated that the fracture appearance transition temperature (50% FATT) for weld metal was −11 °C, while low and scattered absorbed energies determined by different crack growth paths for the heat affected zone of 9Cr were gained which could not satisfy the requirement of service. However, a dramatically enhanced impact toughness was obtained by optimizing the post-weld heat treatment (PWHT) process. Microstructure characterization revealed that the microstructure evolution from martensitic laths in the previous PWHT metals to a softer ferrite matrix with the supersaturated carbon precipitating from the matrix led to higher toughness in the optimized PWHT materials. In addition, the observation of the fracture morphology found that the fractography varied from brittle fracture to a fracture mode with both brittle and ductile fracture feature with the change of crack growth paths in 9Cr-HAZ.

Keywords

the weakest zone in toughnessdissimilar welded jointoptimized PWHTdramatically enhancementmicrostructure evolution
Type
Articles
Information
Journal of Materials Research , Volume 32 , Issue 16 , 28 August 2017 , pp. 3117 - 3127
Check for updates
Copyright
Copyright © Materials Research Society 2017 

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.)

Footnotes

Contributing Editor: Jürgen Eckert

References

REFERENCES

Barella, S., Bellogini, M., Boniardi, M., and Cincera, S.: Failure analysis of a steam turbine rotor. Eng. Failure Anal. 18, 1511–1519 (2011).Google Scholar
Wu, Q., Lu, F., Cui, H., Ding, Y., and Gao, Y.: Microstructure characteristics and temperature-dependent high cycle fatigue behavior of advanced 9% Cr/CrMoV dissimilarly welded joint. Mater. Sci. Eng., A 615, 98–106 (2014).Google Scholar
Long, X., Cai, G., and Svensson, L-E.: Investigation of fracture and determination of fracture toughness of modified 9Cr–1Mo steel weld metals using AE technique. Mater. Sci. Eng., A 270, 260–266 (1999).CrossRefGoogle Scholar
Moitra, A., Parameswaran, P., Sreenivasan, P., and Mannan, S.: A toughness study of the weld heat-affected zone of a 9Cr–1Mo steel. Mater. Charact. 48, 55–61 (2002).Google Scholar
Wang, X., Shi, Q., Wang, X., and Zhang, Z.: The influences of precrack orientations in welded joint of Ti–6Al–4V on fatigue crack growth. Mater. Sci. Eng., A 527, 1008–1015 (2010).Google Scholar
Zhu, M. and Xuan, F.: Effects of temperature on tensile and impact behavior of dissimilar welds of rotor steels. Mater. Des. 31, 3346–3352 (2010).Google Scholar
Gao, Q., Di, X., Liu, Y., and Yan, Z.: Recovery and recrystallization in modified 9Cr–1Mo steel weldments after post-weld heat treatment. Int. J. Pressure Vessels Piping 93, 69–74 (2012).Google Scholar
Aloraier, A., Ibrahim, R., and Ghojel, J.: Eliminating post-weld heat treatment in repair welding by temper bead technique: Role bead sequence in metallurgical changes. J. Mater. Process. Technol. 153, 392–400 (2004).Google Scholar
Wang, H., Zhang, H., and Li, J.: Microstructural evolution of 9Cr–1Mo deposited metal subjected to weld heating. J. Mater. Process. Technol. 209, 2803–2811 (2009).Google Scholar
Bang, K., Park, C., Jung, H., and Lee, J.: Effects of flux composition on the element transfer and mechanical properties of weld metal in submerged arc welding. Met. Mater. Int. 15, 471–477 (2009).Google Scholar
Chao, Y., Ward, J., and Sands, R.: Charpy impact energy, fracture toughness and ductile–brittle transition temperature of dual-phase 590 Steel. Mater. Des. 28, 551–557 (2007).CrossRefGoogle Scholar
Song, S., Zhuang, H., Wu, J., Weng, L., Yuan, Z., and Xi, T.: Dependence of ductile-to-brittle transition temperature on phosphorus grain boundary segregation for a 2.25Cr1Mo steel. Mater. Sci. Eng., A 486, 433–438 (2008).Google Scholar
Ceschini, L., Marconi, A., Martini, C., Morri, A., and Di Schino, A.: Tensile and impact behaviour of a microalloyed medium carbon steel: Effect of the cooling condition and corresponding microstructure. Mater. Des. 45, 171–178 (2013).Google Scholar
Taneike, M., Sawada, K., and Abe, F.: Effect of carbon concentration on precipitation behavior of M23C6 carbides and MX carbonitrides in martensitic 9Cr steel during heat treatment. Metall. Mater. Trans. A 35, 1255–1262 (2004).Google Scholar
You, Y., Shiue, R., Shiue, R., and Chen, C.: The study of carbon migration in dissimilar welding of the modified 9Cr–1Mo steel. J. Mater. Sci. Lett. 20, 1429–1432 (2001).CrossRefGoogle Scholar
Im, Y., Oh, Y., Lee, B., Hong, J., and Lee, H.: Effects of carbide precipitation on the strength and Charpy impact properties of low carbon Mn–Ni–Mo bainitic steels. J. Nucl. Mater. 297, 138–148 (2001).Google Scholar
Zhu, Z., Kuzmikova, L., Marimuthu, M., Li, H., and Barbaro, F.: Role of Ti and N in line pipe steel welds. Sci. Technol. Weld. Joining 18, 1–10 (2013).Google Scholar
Sung, H., Shin, S., Cha, W., Oh, K., Lee, S., and Kim, N.: Effects of acicular ferrite on charpy impact properties in heat affected zones of oxide-containing API X80 linepipe steels. Mater. Sci. Eng., A 528, 3350–3357 (2011).Google Scholar
Guo, A., Li, S., Guo, J., Li, P., Ding, Q., Wu, K., and He, X.: Effect of zirconium addition on the impact toughness of the heat affected zone in a high strength low alloy pipeline steel. Mater. Charact. 59, 134–139 (2008).Google Scholar
Lan, L., Qiu, C., Zhao, D., Gao, X., and Du, L.: Microstructural characteristics and toughness of the simulated coarse grained heat affected zone of high strength low carbon bainitic steel. Mater. Sci. Eng., A 529, 192–200 (2011).Google Scholar
Zhu, Z., Han, J., Li, H., and Lu, C.: High temperature processed high Nb X80 steel with excellent heat-affected zone toughness. Mater. Lett. 163, 171–174 (2016).CrossRefGoogle Scholar
Wang, J., Lu, S., Rong, L., and Li, D.: Effect of silicon contents on the microstructures and mechanical properties of heat affected zones for 9Cr2WVTa steels. J. Nucl. Mater. 470, 1–12 (2016).Google Scholar
Zhang, Z., Wang, Z., Wang, W., Yan, Z., Dong, P., Du, H., and Ding, M.: Microstructure evolution in heat affected zone of T4003 ferritic stainless steel. Mater. Des. 68, 114–120 (2015).Google Scholar
Wang, J., Lu, S., Dong, W., Li, D., and Rong, L.: Microstructural evolution and mechanical properties of heat affected zones for 9Cr2WVTa steels with different carbon contents. Mater. Des. 64, 550–558 (2014).Google Scholar
Sreenivasan, P.: Application of a cleavage fracture stress model for estimating the ASTM E-1921 reference temperature of ferritic steels from instrumented impact test of CVN specimens without precracking. Procedia Eng. 86, 272–280 (2014).CrossRefGoogle Scholar
Norris, S.: The influence of non-metallic inclusions on the prediction of 50% FATT using the miniaturised disk bend test. Int. J. Pressure Vessels Piping 74, 249–258 (1997).Google Scholar
Zhu, M. and Xuan, F.: Correlation between microstructure, hardness and strength in HAZ of dissimilar welds of rotor steels. Mater. Sci. Eng., A 527, 4035–4042 (2010).Google Scholar
Wu, Q., Lu, F., Cui, H., Liu, X., Wang, P., and Tang, X.: Role of butter layer in low-cycle fatigue behavior of modified 9Cr and CrMoV dissimilar rotor welded joint. Mater. Des. 59, 165–175 (2014).Google Scholar
Wu, Q., Lu, F., Cui, H., Liu, X., Wang, P., and Gao, Y.: Soft zone formation by carbon migration and its effect on the high-cycle fatigue in 9% Cr–CrMoV dissimilar welded joint. Mater. Lett. 141, 242–244 (2015).Google Scholar
Ashrafizadeh, S. and Eivani, A.: Correlative evolution of microstructure, particle dissolution, hardness and strength of ultrafine grained AA6063 alloy during annealing. Mater. Sci. Eng., A 644, 284–296 (2015).Google Scholar
Ceschini, L., Morri, A., Morri, A., and Pivetti, G.: Predictive equations of the tensile properties based on alloy hardness and microstructure for an A356 gravity die cast cylinder head. Mater. Des. 32, 1367–1375 (2011).Google Scholar