Journal of Welding and Joining

The Korean Welding and Joining Society (대한용접접합학회)
권호 표지
DOI QR코드

DOI QR Code

Microstructure Evolution and Its Effect on Strength during Thermo-mechanical Cycling in the Weld Coarse-grained Heat-affected Zone of Ti-Nb Added HSLA Steel

Ti-Nb첨가 저합금강 용접열영향부에서의 열-응력 이력이 미세조직 및 기계적 성질에 미치는 영향에 관한 연구

  • Moon, Joonoh (Ferrous Alloy Department, Advanced Metallic Materials Division, Korea Institute of Materials Science) ;
  • Lee, Changhee (Division of Material Science and Engineering, Hanyang University)
  • 문준오 (한국기계연구원 부설 재료연구소 철강재료연구실) ;
  • 이창희 (한양대학교 신소재공학부)
  • Received : 2013.09.26
  • Accepted : 2013.12.12
  • Published : 2013.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

The influence of thermo-mechanical cycling on the microstructure and strength in the weld coarse-grained heat affected zone (CGHAZ) of Ti-Nb added low carbon HSLA steel was explored through Vickers hardness tests, nanoindentation experiments, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Undeformed and deformed CGHAZs were simulated using Gleeble simulator with different heat inputs of 30kJ/cm and 300kJ/cm. At high heat input of 300kJ/cm, the CGHAZ consisted of ferrite and pearlite and then their grain sizes were not affected by deformation. At low heat input of 30kJ/cm, the CGHAZ consisted of lath martensite and then the sizes of prior austenite grain, packet and lath width decreased with deformation. In addition, the fraction of particle increased with deformation and this is because the precipitation kinetics was accelerated by deformation. Meanwhile, the Vickers and nanoindentation hardness of deformed CGHAZ with 30kJ/cm heat input were higher than those of undeformed CGHAZ, which are due to the effect of grain refinement and precipitation strengthening.

Keywords

References

  1. Rodrigues PCM, Pereloma EV, Santos DB: Mechanical properties of an HSLA bainitic steel subjected to controlled rolling with accelerated cooling. Mater. Sci. & Eng. A, 283 (2000), 136-143 https://doi.org/10.1016/S0921-5093(99)00795-9
  2. Kong J, Xie C: Effect of molybdenum on continuous cooling bainite transformation of low-carbon microalloyed steel. Mater. Des., 27 (2006), 1169-1173 https://doi.org/10.1016/j.matdes.2005.02.006
  3. Show BK, Veerababu R, Balamuralikrishnan R, Malakondaiah G: Effect of vanadium and titanium modification on the microstructure and mechanical properties of a microalloyed HSLA steel. Mater. Sci. & Eng. A, 527 (2010), 1595-1604 https://doi.org/10.1016/j.msea.2009.10.049
  4. Kim S, Moon J, Lee Y, Jeong H, Lee C: Prediction model for the microstructure and properties in weld heat affected zone: V. Prediction model for the phase transformation considering the in fluence of prior austenite grain size and cooling rate in weld HAZ of low alloyed steel. Journal of KWJS, 28-3 (2010), 104-113 (in Korean) https://doi.org/10.5781/KWJS.2010.28.3.104
  5. Lee Y, Moon J, Kim S, Lee C: Correlation between M-A constituents and tensile properties in the intercritical coarse grained HAZ of an ultra low carbon steel. Journal of KWJS, 28-3 (2010), 9-103 (in Korean) https://doi.org/10.5781/KWJS.2010.28.3.099
  6. Mohandas T, Madhusudan Reddy G, Satish Kumar B: Heat-affected zone softening in high-strength lowalloy steels. J. Mater. Process. Technol., 88 (1999), 284-294 https://doi.org/10.1016/S0924-0136(98)00404-X
  7. Li Y, Crowther DN, Green MJW, Mitchell PS, Baker TN: The effect of vanadium and niobium on the properties and microstructure of the intercritically reheated coarse grained heat affected zone in low carbon microalloyed steels. ISIJ Int., 41 (2001), 46-55 https://doi.org/10.2355/isijinternational.41.46
  8. Easterling K: Introduction to the physical metallurgy of welding (1st Edition), 1983; 33-35
  9. Moon J, Lee C: Behavior of (Ti,Nb)(C,N) complex particle during Thermo-mechanical cycling in the weld CGHAZ of a microalloyed steel. Acta Mater., 57 (2009), 2311-2320 https://doi.org/10.1016/j.actamat.2009.01.042
  10. Denis S, Archambault P, Gautier E, Simon A, Beck G: Prediction of residual stress and distorsion of ferrous and non-ferrous metals: Current status and future developments. J. Mater. Eng. Performance, 11 (2002), 92-102 https://doi.org/10.1007/s11665-002-0014-2
  11. Easterling K: Introduction to the physical metallurgy of welding (1st Edition), 1983; 23-24
  12. Moon J, Kim S, Lee C: Effect of thermo-mechanical cycling on the microstructure and strength of lath martensite in the weld CGHAZ of HSLA steel. Mater. Sci. & Eng. A, 528 (2011), 7658-7662 https://doi.org/10.1016/j.msea.2011.06.067
  13. Dutta B, Palmiere EJ, Sellars CM: Modelling the kinetics of strain induced predipitation in Nb microalloyed steels. Acta Mater., 49 (2001), 785-794 https://doi.org/10.1016/S1359-6454(00)00389-X
  14. Porter DA, Easterling KE: Phase transformation in metals and alloys (2nd Edition), 2001; 406, 415- 416
  15. Russell KC: Nucleation in solids: the induction and steady state effects. Adv. Colloid Interface Sci., 13 (1980), 205-318 https://doi.org/10.1016/0001-8686(80)80003-0
  16. Moon J, Kim S, Jang J.-I, Lee J, Lee C: Orowan strengthening effect on the nanohardness of the ferrite matrix in microalloyed steels. Mater. Sci. & Eng. A, 487 (2008), 552-557 https://doi.org/10.1016/j.msea.2007.10.046