Thermodynamics formation of oxides in laser powder bed fusion processed aluminum-deoxidized maraging steel and their effects on toughness

Abstract

Maraging steels are ultrahigh-strength, low-carbon steels requiring strict control of impurity elements to ensure optimal strength and toughness. This study aims to elucidate the role of oxygen content in controlling oxide inclusions and cryogenic toughness in laser powder bed fusion (L-PBF) fabricated maraging steels. Two types of powders were used: vacuum induction gas atomization (VIGA) powder with 0.034wt% oxygen and plasma rotating electrode process (PREP) powder with 0.016wt% oxygen. The PREP deposit exhibited finer and more dispersed Al₂O₃ inclusions (average size: (37 ± 11) nm; number density: 7.6 × 10¹⁸ m⁻³) compared to the VIGA deposit ((59 ± 28) nm; 6.5 × 10¹⁸ m⁻³). As a result, the PREP specimens demonstrated significantly improved impact toughness—138 J at 23°C and 65 J at −196°C—representing 53.3% and 47.8% increase over the VIGA specimens, respectively. This difference is due to the lower oxygen content in PREP, leading to lower-temperature nucleation with a reduced nucleation barrier. In addition to quantitatively evaluating the oxygen inclusion–toughness relationship, a thermodynamic model was developed to capture the nucleation and evolution of nanoscale oxides under the rapid thermal cycles characteristic of the L-PBF molten pool, which enables prediction of the size and number density evolution of oxide inclusions under different oxygen levels. These findings offer insights for oxygen-level control and powder design strategies in additive manufacturing of maraging steels.

Keywords

laser powder bed fusion / maraging steels / oxygen content / oxide inclusions / cryogenic toughness

References

[1] Tian ZH, Shang CL, Zhang CL, et al. . Review of precipitation strengthening in ultrahigh-strength martensitic steel. Int. J. Miner. Metall. Mater., 2025, 32(2): 256

[2] Zhang HL, Ji X, Ma DP, et al. . Effect of aging temperature on the austenite reversion and mechanical properties of a Fe–10Cr–10Ni cryogenic maraging steel. J. Mater. Res. Technol., 2021, 11: 98

[3] Wuriti G, Chattopadhyaya S, Thomas T. Acoustic emission test method for investigation of M250 maraging steel pressure vessels for aerospace applications. Mater. Today Proc., 2022, 49: 2176

[4] O. Hentschel, P. Krakhmalev, G. Fredriksson, J. Olsèn, A. Selte, and M. Schmidt, Influence of the in situ heat treatment during manufacturing on the microstructure and properties of DEDLB/M manufactured maraging tool steel, J. Mater. Process. Technol., 315(2023), art. No. 117928.

[5] A.A. Hassen, M. Noakes, P. Nandwana, et al., Scaling up metal additive manufacturing process to fabricate molds for composite manufacturing, Addit. Manuf., 32(2020), art. No. 101093.

[6] Z. Feng, G. Wang, Z.W. Hao, et al., Influence of scale effect on surface morphology in laser powder bed fusion technology, Virtual Phys. Prototyp., 19(2024), No. 1, art. No. e2336157.

[7] Priarone PC, Lunetto V, Atzeni E, Salmi A. Laser powder bed fusion (L-PBF) additive manufacturing: On the correlation between design choices and process sustainability. Procedia CIRP, 2018, 78: 85-90

[8] Mao BY, Liu Y, Ye JW, Chen ZJ. Effect of scanning speed on surface roughness and mechanical properties of 316L stainless steel prepared by selective laser melting. Rare Met. Mater. Eng., 2023, 52(3): 860

[9] Zhang LF, Thomas BG. State of the art in evaluation and control of steel cleanliness. ISIJ Int., 2003, 43(3): 271

[10] Tan JH, Wong WLE, Dalgarno KW. An overview of powder granulometry on feedstock and part performance in the selective laser melting process. Addit. Manuf., 2017, 18: 228

[11] N. Derimow, E. Mansfield, J. Holm, and N. Hrabe, Additive manufacturing titanium powder oxygen variation within a single powder bed due to differences in powder size and oxygen content, Addit. Manuf. Lett., 5(2023), art. No. 100125.

[12] H.Y. Chia, L. Wang, and W.T. Yan, Influence of oxygen content on melt pool dynamics in metal additive manufacturing: High-fidelity modeling with experimental validation, Acta Mater., 249(2023), art. No. 118824.

[13] Sun Y, Hebert RJ, Aindow M. Non-metallic inclusions in 17–4PH stainless steel parts produced by selective laser melting. Mater. Des., 2018, 140: 153

[14] Yan FY, Xiong W, Faierson E, Olson GB. Characterization of nano-scale oxides in austenitic stainless steel processed by powder bed fusion. Scripta Mater., 2018, 155: 104

[15] Gu C, Bao YP, Gan P, Wang M, He JS. Effect of main inclusions on crack initiation in bearing steel in the very high cycle fatigue regime. Int. J. Miner. Metall. Mater., 2018, 25(6): 623

[16] M.P. Haines, N.J. Peter, S.S. Babu, and E.A. Jägle, In-situ synthesis of oxides by reactive process atmospheres during L-PBF of stainless steel, Addit. Manuf., 33(2020), art. No. 101178.

[17] Saeidi K, Kvetková L, Lofaj F, Shen ZJ. Austenitic stainless steel strengthened by the in situ formation of oxide nanoinclusions. RSC Adv., 2015, 5(27): 20747

[18] Lou XY, Andresen PL, Rebak RB. Oxide inclusions in laser additive manufactured stainless steel and their effects on impact toughness and stress corrosion cracking behavior. J. Nucl. Mater., 2018, 499: 182

[19] Cooper AJ, Cooper NI, Dhers J, Sherry AH. Effect of oxygen content upon the microstructural and mechanical properties of type 316L austenitic stainless steel manufactured by hot isostatic pressing. Metall. Mater. Trans. A, 2016, 47(9): 4467

[20] G. Liu, J. Su, A. Wang, et al., A novel Fe–Cr–Ni–Co–Mo maraging stainless steel with enhanced strength and cryogenic toughness: Role of austenite with core-shell structures, Mater. Sci. Eng. A, 863(2023), art. No. 144537.

[21] W.T. Li, J. Chai, G. Liu, et al., On the role of chemically heterogeneous austenite in cryogenic toughness of maraging steels manufactured via laser powder bed fusion, Acta Mater., 276(2024), art. No. 120157.

[22] Wu LZ, Zhang C, Khan DF, et al. . Unveiling the cellular microstructure–property relations in martensitic stainless steel via laser powder bed fusion. Int. J. Miner. Metall. Mater., 2024, 31(11): 2476

[23] Goto H, Miyazawa KI, Tanaka K. Effect of oxygen content on size distribution of oxides in steel. ISIJ Int., 1995, 35(3): 286

[24] Kampmann L, Kahlweit M. On the theory of precipitations II zur theorie von Fällungen II. Ber. Bunsenges. Phys. Chem., 1970, 74(5): 456

[25] Myhr OR, Grong Ø. Modelling of non-isothermal transformations in alloys containing a particle distribution. Acta Mater., 2000, 48(7): 1605

[26] Zhang J, Lee HG. Numerical modeling of nucleation and growth of inclusions in molten steel based on mean processing parameters. ISIJ Int., 2004, 44(10): 1629

[27] Kashchiev D. Nucleation Basic Theory With Applications, 2000,

[28] D.R. Eo, S.G. Chung, J. Yang, I.H. Jung, and J.W. Cho, Numerical modeling of oxide particle evolution during additive manufacturing, Addit. Manuf., 51(2022), art. No. 102631.

[29] N.A. Wassermann, Y.C. Li, A.J. Myers, et al., Limits of dispersoid size and number density in oxide dispersion strengthened alloys fabricated with powder bed fusion-laser beam, Addit. Manuf., 81(2024), art. No. 104022.

[30] Perez M, Dumont M, Reyes DA. Implementation of classical nucleation and growth theories for precipitation. Acta Mater., 2008, 56(9): 2119

[31] Z.N. Wang, X. Lin, L.L. Wang, Y. Cao, Y.H. Zhou, and W.D. Huang, Microstructure evolution and mechanical properties of the wire + arc additive manufacturing Al–Cu alloy, Addit. Manuf., 47(2021), art. No. 102298.

[32] Babu SS, David SA, Vitek JM, Mundra K, DebRoy T. Development of macro- and microstructures of carbon–manganese low alloy steel welds: Inclusion formation. Mater. Sci. Technol., 1995, 11(2): 186

[33] Wakoh M, Sano N. Behavior of alumina inclusions just after deoxidation. ISIJ Int., 2007, 47(5): 627

[34] Ohta H, Suito H. Effects of dissolved oxygen and size distribution on particle coarsening of deoxidation product. ISIJ Int., 2006, 46(1): 42

[35] Zhang LF, Pluschkell W. Nucleation and growth kinetics of inclusions during liquid steel deoxidation. Ironmaking Steelmaking, 2003, 30(2): 106

[36] Zeldovich YB. Selected Works of Yakov Borisovich Zeldovich, Volume I: Chemical Physics and Hydrodynamics, 1992, Princeton. Princeton University Press

[37] Hong T, Debroy T. Nonisothermal growth and dissolution of inclusions in liquid steels. Metall. Mater. Trans. B, 2003, 34(2): 267

[38] Perez M. Gibbs–Thomson effects in phase transformations. Scripta Mater., 2005, 52(8): 709

[39] Garcia AL, Broeck CVD, Aertsens M, Serneels R. A Monte Carlo simulation of coagulation. Physica A, 1987, 143(3): 535

[40] Tozawa H, Kato Y, Sorimachi K, Nakanishi T. Agglomeration and flotation of alumina clusters in molten steel. ISIJ Int., 1999, 39(5): 426

[41] Lei H, Nakajima K, He JC. Mathematical model for nucleation, Ostwald ripening and growth of inclusion in molten steel. ISIJ Int., 2010, 50(12): 1735

[42] Gasper AND, Szost B, Wang X, et al. . Spatter and oxide formation in laser powder bed fusion of Inconel 718. Addit. Manuf., 2018, 24: 446

[43] Ladewig A, Schlick G, Fisser M, Schulze V, Glatzel U. Influence of the shielding gas flow on the removal of process by-products in the selective laser melting process. Addit. Manuf., 2016, 10: 1

[44] Zhong Y, Liu LF, Zou J, Li XD, Cui DQ, Shen ZJ. Oxide dispersion strengthened stainless steel 316L with superior strength and ductility by selective laser melting. J. Mater. Sci. Technol., 2020, 42: 97

[45] G. Wang, Y.M. Zhang, B.K. Zou, et al., Enhanced plasticity due to melt pool flow induced uniform dispersion of reinforcing particles in additively manufactured metallic composites, Int. J. Plast., 164(2023), art. No. 103591.

RIGHTS & PERMISSIONS

University of Science and Technology Beijing