Study of Nb non-equilibrium segregation at prior austenite grain boundary in welding using atom probe tomography and modeling
Source abstract
Abstract
The non-equilibrium segregation of Nb at prior austenite grain boundary (PAGB) induced by welding is experimentally investigated by means of atom probe tomography (APT). The Nb concentration at PAGB appeared to be 0.115 at.% for experimental steel containing 0.06 at.% Nb at the simulated welding thermal cycle for 10 s from 1320 to 950 °C. The critical time tc for achieving maximum segregation is calculated to be 565 s for the experimental steel. For the first time, the diffusion coefficient of Nb in desegregation process is calculated for the temperature of Ti = 950 °C using non-equilibrium segregation model and APT experimental result and is confirmed to be 9.23 × 10−11 m2/s. Based on it, the kinetics of Nb non-equilibrium segregation at the PAGBs in welding process is outlined, and the segregation process and desegregation process are discussed. The Nb segregation at PAGB is also predicted over the t8/5 range of 3–600 s. The critical t8/5, at which the highest Nb concentration of 0.144 at.% at PAGB is predicted to be achieved, is ~ 29 s.
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Research context
OpenAlex topics: Advanced Materials Characterization Techniques · Hydrogen embrittlement and corrosion behaviors in metals · Microstructure and Mechanical Properties of Steels
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (33)
Show source-provided references
1. Schino AD, Nunzio PED (2017) Effect of Nb microalloying on the heat affected zone microstructure of girth welded joints. Mater Lett 186:86–8910.1016/j.matlet.2016.09.092 ↗
2. Kumar S, Nath SK, Kumar V (2016) Continuous cooling transformation behavior in the weld coarse-grained heat affected zone and mechanical properties of Nb-microalloyed and HY85 steels. Mater Des 90:177–18410.1016/j.matdes.2015.10.071 ↗
3. Kirkwood P (2015) Welding niobium bearing HSLA steel ‘myths and magic’, microalloying 2015, vol 11. Chinese Society for Metals (CSM), The Chinese Academy of Engineering (CAE), Hangzhou, p 439
4. Chen XW, Liao B, Qiao GY, Gu Y, Wang X, Xiao FR (2013) Effect of Nb on mechanical properties of HAZ for high-Nb X80 pipeline Steels. ISIJ Int 20(12):53–60
5. Zhang YQ, Zhang HQ, Liu WM, Hou H (2009) Effects of Nb on microstructure and continuous cooling transformation of coarse grain heat-affected zone in 610 MPa class high-strength low-alloy structural steels. Mater Sci Eng A 499(1–2):182–18610.1016/j.msea.2007.10.118 ↗
6. Suehiro M, Liu ZK, Ågren J (1996) Effect of niobium on massive transformation in ultra-low carbon steels: a solute drag treatment. Acta Mater 44(10):4241–425110.1016/S1359-6454(96)00036-5 ↗
7. Maruyama N, Smith GDW (2005) 3DAP analysis on solute segregation of Nb and Mo during primary recrystallization of α-Fe. Nippon Steel Tech Rep 91:34–37
8. Furuhara T, Yamaguchi T, Miyamoto G, Maki T (2010) Incomplete transformation of upper bainite in Nb bearing low carbon steels. Mater Sci Technol Lond 26(4):392–39710.1179/026708309X12512744 ↗
9. Takayama N, Miyamoto G, Furuhara T (2018) Chemistry and three-dimensional morphology of martensite-austenite constituent in the bainite structure of low-carbon low-alloy steels. Acta Mater 145:154–16410.1016/j.actamat.2017.11.036 ↗
10. Thomas MH, Michal GM (1981) Solid–solid phase transformations. TMS-AIME, Warrendale, pp 469–473
11. Fossaert C, Rees G, Maurickx T, Bhadeshia HKDH (1995) The effect of niobium on the hardenability of microalloyed austenite. Metall Mater Trans A 26:21–3010.1007/BF02669791 ↗
12. Li Y, Crowther DN, Green MJW, Mitchell PS, Baker TN (2001) 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(1):46–5510.2355/isijinternational.41.46 ↗
13. Xu TD, Cheng BY (2004) Kinetics of non-equilibrium grain-boundary segregation. Prog Mater Sci 2(49):109–208
14. Aust KT, Hanneman RE, Niessen P, Westbrook JH (1968) Solute induced hardening near grain boundaries in zone refined metals. Acta Metall 16(3):291–30210.1016/0001-6160(68)90014-X ↗
15. Anthony TR (1969) Solute segregation in vacancy gradients generated by sintering and temperature changes. Acta Metall 17(5):603–60910.1016/0001-6160(69)90120-5 ↗
16. Hanneman RE, Anthony TR (1969) Effects of non-equilibrium segregation on near-surface diffusion. Acta Metall 17(9):1133–114010.1016/0001-6160(69)90089-3 ↗
17. Miller MK (2000) Atom probe tomography: analysis at the atomic level. Kluwer Academic, New York, p 110.1007/978-1-4615-4281-0 ↗
18. Felfer PJ, Killmore CR, Williams JG, Carpenter KR, Ringer SP, Cairney JM (2012) A quantitative atom probe study of the Nb excess at prior austenite grain boundaries in a Nb microalloyed strip-cast steel. Acta Mater 60(13–14):5049–505510.1016/j.actamat.2012.06.013 ↗
19. Li XD, Shang CJ, Ma XP, Gault B, Subramanian SV, Sun JB, Misra RDK (2017) Elemental distribution in the martensite–austenite constituent in intercritically reheated coarse-grained heat-affected zone of a high-strength pipeline steel. Scr Mater 139:67–7010.1016/j.scriptamat.2017.06.017 ↗
20. Miller MK, Forbes RG (2014) Atom-probe tomography: the local electrode atom probe. Springer, Boston, pp 229–25810.1007/978-1-4899-7430-3_5 ↗
21. Aust KT, Westbrook JH (1965) Lattice defects in quenched metals. Academic Press, New York
22. Song SH, Weng LQ (2005) An FEGSTEM study of grain boundary segregation of phosphorus during quenching in a 2.25Cr–1Mo steel. J Mater Sci Technol 21(4):445–45010.1179/174328405X36566 ↗
23. Xu TD, Song SH (1989) A kinetic model of non-equilibrium grain-boundary segregation. Acta Metall 37(9):2499–250610.1016/0001-6160(89)90048-5 ↗
24. Song SH, Xu TD, Yuan ZX (1989) Determination of critical time and critical cooling rate of non-equilibrium grain-boundary segregation. Acta Metall 37(1):319–32310.1016/0001-6160(89)90290-3 ↗
25. Doig P, Flewitt PEJ (1981) Segregation of chromium to prior austenite boundaries during quenching of a 21/4%Cr–l%Mo steel. Acta Metall 29(11):1831–184110.1016/0001-6160(81)90109-7 ↗
26. Geise J, Herzig C, Metalkunde Z (1985) Lattice and grain boundary diffusion of Nb in iron. Z Metallkd 76:622–626
27. Hulka K, Gray JM, Heisterkamp F (1990) Niobium technical report. NBTR 16/90, August 1990, p. B-9 and 43
28. Kim SM, Buyers WJL (1978) Vacancy formation energy in iron by positron annihilation. J Phys F Metal Phys 8(5):L103–L10810.1088/0305-4608/8/5/001 ↗
29. Chapman MAV, Faulkner RG (1983) Computer modelling of grain boundary segregation. Acta Metall 31(5):677–68910.1016/0001-6160(83)90083-4 ↗
30. Faulkner RG (1985) Impurity diffusion constants and vacancy–impurity binding energies in solids. Mater Sci Technol 1(6):442–44710.1179/mst.1985.1.6.442 ↗
31. Faulkner RG, Song SH, Flewitt PEJ (1996) Determination of impurity point defect binding energies in alloys. Mater Sci J 12(11):904–910
32. Faulkner RG (1981) Non-equilibrium grain-boundary segregation in austenitic alloys. J Mater Sci 16(2):373–383. https://doi.org/10.1007/BF0073862610.1007/BF00738626 ↗
33. Hu GX, Cai X (2000) Fundamentals of materials science, vol 4. Shanghai Jiao Tong University Press, Shanghai, p 135