Effect of electromagnetic stirring on microstructure formation in 12%Ni steel ESW weld metal
Tóm tắt
Liquefied natural gas (LNG) has recently received much attention worldwide because of environmental concerns. In general, users and fabricators use high-cost welding materials such as Ni-based weld metals. For highly efficient welding and lower cost welding materials, our research group are developing 12%Ni steel weld metals for electroslag welding (ESW). However, it has reported that the Charpy impact energies decreased as notch position approached the final solidification part in ESW. To improve microstructure at this position, electromagnetic stirring (EMS) is applied for ESW in this study. In the weld metal with EMS, equiaxed prior-γ grains were formed at the final solidification part. The shape of the solidification structure was changed from columnar to equiaxed. This result indicates that change of convection in molten metal by EMS induces dendrite fragmentation and the equiaxed grains are formed. In addition, the number density of inclusions in the weld metal decreased by EMS. From results of the simulation, it is suggested that interaction of inclusions changes depending on distribution of flow velocity in molten metal.
Tài liệu tham khảo
Kakizaki T, Ishizaki K (2021) Development of new electroslag welding method and study of application to 9% Ni steel. J Jpn Weld Soc 90:430–435. https://doi.org/10.2207/jjws.90.430
Kakizaki T, Koga S, Yamamoto H et al (2022) Microstructure features and formation mechanism in a newly developed electroslag welding. Weld World 66:313–324. https://doi.org/10.1007/s40194-021-01215-y
Iwata H, Yamada K, Fujita T (1976) Electromagnetic stirring of molten core in continuous casting of high carbon steel. Trans Iron Steel Inst Jpn 16:374–381. https://doi.org/10.2355/isijinternational1966.16.374
Ayata K, Mori T, Fujimoto T et al (1984) Improvement of macrosegregation in continuously cast bloom and billet by electromagnetic stirring. Trans Iron Steel Inst Jpn 24:931–939. https://doi.org/10.2355/isijinternational1966.24.931
Kawai S, Wang Q, Iwai K et al (2001) Generation of compression waves by simultaneously imposing a static magnetic field and an alternating current and its use for refinement of solidified structure. Mater Trans 42:275–280. https://doi.org/10.2320/matertrans.42.275
Chernysh VP, Kuznetsov VD, Kazakov NK et al (1981) The use of electromagnetic stirring for increasing the quality of electroslag joints. Chem Pet Eng 17:160–162. https://doi.org/10.1007/BF01157957
Bhadeshia HKDH (2001) Bainite in steels, 2nd edn. Institute of Materials, London
Petch NJ (1958) The ductile-brittle transition in the fracture of α-iron: I. Philos Mag 3:1089–1097. https://doi.org/10.1080/14786435808237038
Qiu H, Ito R, Hiraoka K (2006) Role of grain size on the strength and ductile-brittle transition temperature in the dual-sized ferrite region of the heat-affected zone of ultra-fine grained steel. Mater Sci Eng A 435–436:648–652. https://doi.org/10.1016/j.msea.2006.07.086
Qiu H, Hanamura T, Torizuka S (2014) Influence of grain size on the ductile fracture toughness of ferritic steel. ISIJ int 54:1958–1964. https://doi.org/10.2355/isijinternational.54.1958
Raghavan V (1994) Cr-Fe-Ni (chromium-iron-nickel). J Phase Equilibria 15:534–538. https://doi.org/10.1007/BF02649411
Agusa K, Kosho M, Nishiyama N (1984) Transformation behavior of ferritic weld metal in 9% Ni steel. Q J Jpn Weld Soc 2:483–490. https://doi.org/10.2207/qjjws.2.483
Miyamoto G, Takayama N, Furuhara T (2009) Accurate measurement of the orientation relationship of lath martensite and bainite by electron backscatter diffraction analysis. Scr Mater 60:1113–1116. https://doi.org/10.1016/j.scriptamat.2009.02.053
Miyamoto G, Iwata N, Takayama N (2010) Mapping the parent austenite orientation reconstructed from the orientation of martensite by EBSD and its application to ausformed martensite. Acta Mater 58:6393–6403. https://doi.org/10.1016/j.actamat.2010.08.001
Kitahara H, Ueji R, Tsuji N (2006) Crystallographic features of lath martensite in low-carbon steel. Acta Mater 54:1279–1288. https://doi.org/10.1016/j.actamat.2005.11.001
Morito S, Tanaka H, Konishi R et al (2003) The morphology and crystallography of lath martensite in Fe-C alloys. Acta Mater 51:1789–1799. https://doi.org/10.1016/S1359-6454(02)00577-3
Cayron C, Artaud B, Briottet L (2006) Reconstruction of parent grains from EBSD data. Mater Charact 57:386–401. https://doi.org/10.1016/j.matchar.2006.03.008
Inoue H, Koseki T (2007) Clarification of solidification behaviors in austenitic stainless steels based on welding process. Nippon Steel Tech Rep 95:62–70
Ruvalcaba D, Mathiesen RH, Eskin DG et al (2007) In situ observations of dendritic fragmentation due to local solute-enrichment during directional solidification of an aluminum alloy. Acta Mater 55:4287–4292. https://doi.org/10.1016/j.actamat.2007.03.030
Wang S, Kang J, Zhang Z et al (2018) Dendrites fragmentation induced by oscillating cavitation bubbles in ultrasound field. Ultrason 83:26–32. https://doi.org/10.1016/j.ultras.2017.08.004
Liu X, Osawa Y, Takamori S (2008) Microstructure and mechanical properties of AZ91 alloy produced with ultrasonic vibration. Mater Sci Eng A 487:120–123. https://doi.org/10.1016/j.msea.2007.09.071
Eskin GI (1994) Influence of cavitation treatment of melts on the processes of nucleation and growth of crystals during solidification of ingots and castings from light alloys. Ultrason Sonochem 1:S59–S63. https://doi.org/10.1016/1350-4177(94)90029-9
Sasai K (2022) Kinetics on formation, growth, and removal of alumina inclusions in molten steel. ISIJ int 62:426–436. https://doi.org/10.2355/isijinternational.ISIJINT-2021-475
Miyazawa K (2001) Continuous casting of steels in Japan. Sci Technol Adv Mater 2:59–65. https://doi.org/10.1016/S1468-6996(01)00026-2