Microstructure and Properties of Fe-12Cr-2.5W-xSi-0.4Ti-0.3Y₂O₃ Alloys

Abstract

Fe-12Cr-2.5W-xSi-0.4Ti-0.3Y₂O₃ alloys were fabricated by mechanical alloying and vacuum sintering. The effect of sintering temperature and Si content on the microstructure and properties of the alloy was investigated systematically. The experimental results show that the relative density and tensile strength of the alloy were increased with the elevating of sintering temperature and Si content within a certain range. The alloy with 1wt% Si sintered at 1 350 °C exhibited superior properties, and the relative density and tensile strength were 96.8% and 692.7 MPa, respectively. HAADF and EDAX analysis of nano-precipitation in the matrix indicated that Si could combine with Y, Ti, and O in the sintering process, which was uniformly distributed with the size of 10 nm. Portion of Y₂O₃ had not completely dissolved in the milling process, which was retained in the matrix of the alloy.

Keywords

sintering temperature / Si content / nano-precipitates / tensile strength

References

[1] Gil E, Ordás N, García-Rosales C, et al. Microstructural Characterization of ODS Ferritic Steels at Different Processing Stages. Fusion Engineering and Design, 2015, 98–99: 1 973-1 977. J]

[2] Oksiuta Z, Boehm-Courjault E, Baluc N. Relation between Microstructure and Charpy Impact Properties of an Elemental and Pre-alloyed 14Cr ODS Ferritic Steel Powder after Hot Isostatic Pressing. Journal of Material Science, 2010, 45(14): 3 921-3 930. J]

[3] Klueh RL, Gelles DS, Jitsukawa S, et al. Ferritic/Martensitic Steels-Overview of Recent Results. Journal of Nuclear Materials, 2002, 307–311: 455-465. J]

[4] Oksiuta Z, Ozieblo A, Perkowski K, et al. Influence of HIP Pressure on Tensile Properties of a 14Cr ODS Ferritic Steel. Fusion Engineering and Design, 2014, 89(2): 137-141. J]

[5] Ohtsuka S, Ukai S, Fujiwara M, et al. Nano-structure Control in ODS Martensitic Steels by Means of Selecting Titanium and Oxygen Contents. Journal of Physicals and Chemistry of Solids, 2005, 66: 571-575. J]

[6] Alinger MJ, Odette GR, Hoelzer DT. On the Rrole of Alloy Composition and Processing Parameters in Nanocluster Formation and Dispersion Strengthening in Nanostuctured Ferritic Alloys. Acta Materialia, 2009, 57: 392-406. J]

[7] Ukai S, Fujisawa M. Perspective of ODS Alloys Application in Nuclear Environments. Journal of Nuclear Materials, 2002, 307–311: 749-757. J]

[8] Unocic KA, Pint BA, Hoelzer DT. Advanced TEM Characterization of Oxide Nanoparticles in ODS Fe-12Cr-5Al Alloys. Journal of Material Science, 2016, 51(20): 9 190-9 206. J]

[9] Lin X, Li MW, Zhong YS. Microstructure and Hardness of Nanocrystalline Ferritic ODS Alloy Foil with High Oxide Content Fabricated by EBPVD. Applied Surface Science, 2013, 284(1): 679-682. J]

[10] Kondo M. Oxide Dispersion Strengthened Steel and The Fabrication Method[P]. JP-335771, 1999

[11] Dai L, Liu YC, Ma ZQ, Dong ZZ. Microstructural Evolution of Oxide-Dispersion-Strengthened Fe-Cr Model Steels during Mechanical Milling and Subsequent Hot Pressing. Journal of Material Science, 2013, 48(4): 1 826-1 836. J]

[12] Xing H, Sun J, Huang J, et al. Structure and Elastic Property of Nanosized Complex Oxide Particles in Ferritic/Martensitic Alloy: An Electron Energy-Loss Spectroscopy Study. Journal of Nuclear Materials, 2011, 416: 331-334. J]

[13] Bolton JD, Jeandin M, Jouanny TC. Mechanisms of Sintering in High Speed Steels with Phosphorus Alloying Additions. Powder Metallurgy, 1990, 33(2): 126-132. J]

[14] Bolton JD, Gant AJ. Microstructural Development and Sintering Kinetics in Ceramic Reinforced High Speed Steel Metal Matrix Composites. Powder Metallurgy, 1997, 40(2): 143-151. J]

[15] Bolton JD, Petty ER, Allen GB. The Mechanical Properties of α-Phase Low-Carbon Fe-Mn alloys. Powder Metallurgy, 1971, 2(10): 2 915-2 923. [J]

[16] Bolton JD, Youseffi M, Becker BS. Silicide Phase Formation and Its Influence on Liquid Phase Sintering in 316L Stainless Steel with Elemental Silicon Additions. Powder Metallurgy, 1998, 2: 93-101. J]

[17] Tan ZQ, Chen ZZ, Fan GL, et al. Effect of Particle Size on the Thermal and Mechanical Properties of Aluminum Composites Reinforced with SiC and Diamond. Materials and Design, 2016, 90(15): 845-851. J]

[18] Lou JH, Yang YQ, Liu SQ. Microstructure and Mechanical Properties of AZ31 Alloys Processed by Residual Heat Rolling. Journal of Wuhan University of Technology-Materials Science Edition, 2017, 36(4): 588-594. J]

[19] Xu HJ, Lu Z, Wang DM, Liu CM. Nanostructure Evolution in ODS Steels under Ion Irradiation. Nuclear Material Energy, 2016, 9: 66-74. J]