Effect of Ti Content on Microstructure and Hardness of an Austenitic 15Cr-ODS Alloy

doi:10.11901/1005.3093.2025.137

Chinese Journal of Materials Research

2026, Vol. 40

Issue (4): 295-304 DOI: 10.11901/1005.3093.2025.137

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Effect of Ti Content on Microstructure and Hardness of an Austenitic 15Cr-ODS Alloy

CAO Yi¹^,², LI Jing²(

), XIONG Liangyin², LIU Shi², ZHANG Chunhua¹(

)

^1.School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
^2.Shi -changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China

Cite this article:

CAO Yi, LI Jing, XIONG Liangyin, LIU Shi, ZHANG Chunhua. Effect of Ti Content on Microstructure and Hardness of an Austenitic 15Cr-ODS Alloy. Chinese Journal of Materials Research, 2026, 40(4): 295-304.

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Abstract

An austenitic oxide dispersion strengthened (ODS) alloy with the composition of Fe-15Ni-15Cr-2.0Mo-1.0Mn-(0.2, 0.8, 1.5) Ti-0.4Y₂O₃ was fabricated using mechanical alloying and hot isostatic pressing (HIP). The effect of Ti content on the microstructure and microhardness of austenitic 15Cr-ODS alloy was studied through SEM, EBSD, TEM, and microhardness tester. The results show that the increase of Ti content significantly facilitates the formation of Y-Ti-O complex oxide particles. When the Ti content approaches 0.8% (mass fraction), the size of oxide particles in the matrix is mainly concentrated in the range from 2 nm to 7 nm. These nano oxideparticles nanoparticles are mainly composed of Y₂Ti₂O₇ with pyrochlore structure and Y₂TiO₅ with orthogonal structure. Due to the strong pinning effect of nano oxide-particles to grain boundaries, the grain refinement is achieved in the ODS alloy with 0.8% addition of Ti. At the same time, the microhardness of the alloy is increased from 302.7HV_0.5(0.2%Ti) to 401.3HV_0.5 (0.8%Ti). However, when Ti increases to 1.5%, the excessive Ti leads to the formation of coarse TiO₂ particles in addition to Y₂Ti₂O₇ and Y₂TiO₅, which leads to increased grain size and decreased hardness of the alloy. It is proven that the nano oxideparticles with homogenous distribution and fine size can be obtained in the 15Cr-FeCrNi ODS alloy when the contents of Ti and Y₂O₃ are about 0.8% and 0.4% (mass fraction), respectively, thus providing better mechanical properties.

Key words: synthesizing and processing technics for materials 15Cr-ODS austenitic alloy hot isostatic pressing Ti content microstructure microhardness

Received: 14 April 2025

ZTFLH:

TG142.7

Fund: Lingchuang Research Project of China National Nuclear Corporation(CNNC-LCKY-2024-094)

Corresponding Authors: LI Jing, Tel: 15140168377, E-mail: jingli@imr.ac.cn;
ZHANG Chunhua, Tel: 13709840616, E-mail: zhangchunhua5858@126.com

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https://www.cjmr.org/EN/10.11901/1005.3093.2025.137 OR https://www.cjmr.org/EN/Y2026/V40/I4/295

Fig.1 Inverse pole figure (IPF) maps and grain size distribution of as-HIPed ODS alloys (a) 0.2Ti, (b) 0.8Ti, (c) 1.5Ti

Fig.2 Kernel average misorientation (KAM) maps of as-HIPed ODS alloys (a) 0.2Ti, (b) 0.8Ti, (c) 1.5Ti

Fig.3 TEM bright field images and size distribution of oxide particle (a) 0.2Ti, (b) 0.8Ti, (c) 1.5Ti

Fig.4 HRTEM image of oxide particles and corresponding FFT pattern in 0.2Ti alloy (a) Y₂Ti₂O₇, (b) Y₂TiO₅, (c) Y₂O₃

Fig.5 HRTEM image of oxide particles and corresponding FFT pattern in 0.8Ti alloy (a) Y₂Ti₂O₇, (b) Y₂TiO₅

Fig.6 HRTEM image of oxide particles and corresponding FFT pattern in 1.5Ti alloy (a) Y₂Ti₂O₇, (b)Y₂TiO₅, (c) TiO₂

Fig.4a	d₁{ $2 ¯ 2 ¯ 2 ¯$ } / nm	d₂{ $400$ } / nm	d₃{2 $2 ¯ 2 ¯$ } / nm	α₁₂	α₂₃	α₁₃
Measured	0.2862	0.2552	0.2808	123.88°	53.60°	69.43°
Y₂Ti₂O₇	0.2912	0.2522	0.2912	125.26°	54.73°	70.52°
Fig.4b	d₁{ $2 ¯ 1 ¯ 1 ¯$ } / nm	d₂{403} / nm	d₃{2 $1 ¯$ 2} / nm	α₁₂	α₂₃	α₁₃
Measured	0.3003	0.2156	0.2646	127.07°	45.20°	81.86°
Y₂TiO₅	0.2907	0.2129	0.2653	127.53°	46.36°	81.16°
Fig.4c	d₁{ $4 ¯ 2 ¯ 2 ¯$ } / nm	d₂{ $1 ¯ 1 ¯$ 2} / nm	d₃{ $5 ¯ 3 ¯$ 0} / nm	α₁₂	α₂₃	α₁₃
Measured	0.2393	0.4311	0.1858	81.89°	54.16°	24.73°
Y₂O₃	0.2363	0.4327	0.1817	80.40°	55.93°	24.46°

Table 1 Measured values of interplanar spacing (d) and angle (α) for the oxide particle in Fig.4 and the theoretical values

Fig.5a	d₁{ $4 ¯$ 00} / nm	d₂{2 $2 ¯ 2 ¯$ } / nm	d₃{ $2 ¯ 2 ¯ 2 ¯$ } / nm	α₁₂	α₂₃	α₁₃
Measured	0.2578	0.2803	0.2819	125.57°	70.34°	54.32°
Y₂Ti₂O₇	0.2522	0.2912	0.2912	125.26°	70.52°	54.73°
Fig.5b	d₁{ $4 ¯ 1 ¯ 1 ¯$ } / nm	d₂{01 $2 ¯$ } / nm	d₃{ $4 ¯$ 0 $3 ¯$ } / nm	α₁₂	α₂₃	α₁₃
Measured	0.2058	0.3001	0.1980	110.74°	71.12°	39.61°
Y₂TiO₅	0.2083	0.3091	0.2029	111.63°	71.81°	39.82°

Table 2 Measured values of interplanar spacing (d) and angle (α) for the oxide particle in Fig.5 and the theoretical values

Fig.6a	d₁{ $2 ¯ 2 ¯ 2 ¯$ } / nm	d₂{400} / nm	d₃{2 $2 ¯ 2 ¯$ } / nm	α₁₂	α₂₃	α₁₃
Measured	0.3070	0.2541	0.2964	126.27°	53.65°	69.61°
Y₂Ti₂O₇	0.2912	0.2522	0.2912	125.26°	54.73°	70.52°
Fig.6b	d₁{ $2 ¯ 1 ¯ 2 ¯$ } / nm	d₂{ $2 ¯$ 21} / nm	d₃{ $4 ¯$ 1 $1 ¯$ } / nm	α₁₂	α₂₃	α₁₃
Measured	0.2690	0.1721	0.2135	123.52°	38.99°	84.53°
Y₂TiO₅	0.2653	0.1721	0.2083	124.68°	40.21°	84.46°
Fig.6c	d₁{ $1 ¯$ 00} / nm	d₂{00 $1 ¯$ } / nm	d₃{ $1 ¯$ 0 $1 ¯$ } / nm	α₁₂	α₂₃	α₁₃
Measured	0.4592	0.2892	0.2576	89.55°	33.34°	56.77°
TiO₂	0.4594	0.2959	0.2487	90.00°	32.78°	57.21°

Table3 Measured values of interplanar spacing (d) and angle (α) for the oxide particle in Fig.6 and the theoretical values

Table 4 Types and quantities of oxide particles in three alloys

Fig.7 Microhardness values of ODS alloys

Fig.8 Schematic diagram of oxide formation in austenitic ODS steels with different Ti contents

Alloy	Types of oxide	δ / %	$r s t$ / J·m^-2
0.2Ti	Y₂Ti₂O₇	5.1	0.42
	Y₂TiO₅	4.2	0.36
	Y₂O₃	10.6	0.71
0.8Ti	Y₂Ti₂O₇	5.6	0.45
	Y₂TiO₅	0.2	0.02
1.5Ti	Y₂Ti₂O₇	5.5	0.44
	Y₂TiO₅	3.9	0.34
	TiO₂	-	-

Table 5 δ and

r s t

values of oxide particles in three alloys

[1]	Oka H, Watanabe M, Kinoshita H, et al. In situ observation of damage structure in ODS austenitic steel during electron irradiation [J]. J. Nucl. Mater., 2011, 417(1-3): 279
[2]	Velikodnyi A N, Voyevodin V N, Kalchenko A S, et al. Impact of nano-oxides and injected gas on swelling and hardening of 18Cr10NiTi stainless steel during ion irradiation [J]. J. Nucl. Mater., 2022, 565: 153666
[3]	Zhao Q, Yu L M, Liu Y C, et al. Morphology and structure evolution of Y₂O₃ nanoparticles in ODS steel powders during mechanical alloying and annealing [J]. Adv. Powder Technol., 2015, 26: 1578
[4]	Ukai S, Harada M, Okada H, et al. Alloying design of oxide dispersion strengthened ferritic steel for long life FBRs core materials [J]. J. Nucl. Mater., 1993, 204: 65
[5]	Kim I S, Choi B Y, Kang C Y, et al. Effect of Ti and W on the mechanical properties and microstructure of 12%Cr base mechanical-alloyed nano-sized ODS ferritic alloys [J]. ISIJ Int., 2003, 43: 1640
[6]	Oksiuta Z, Baluc N L. Role of Cr and Ti contents on the microstructure and mechanical properties of ODS ferritic steels [J]. Adv. Mater. Res., 2008, 59: 308
[7]	He P, Klimenkov M, Lindau R, et al. Characterization of precipitates in nano structured 14%Cr ODS alloys for fusion application [J]. J. Nucl. Mater., 2012, 428: 131
[8]	Fan L L, Xiong Y K, Zeng Y, et al. The strength-ductility synergy of magnesium matrix nanocomposite achieved by a dual-heterostructure [J]. J. Mater. Sci. Technol., 2025, 215: 296
[9]	Wang M, Sun H Y, Zou L, et al. Structural evolution of oxide dispersion strengthened austenitic powders during mechanical alloying and subsequent consolidation [J]. Powder Technol., 2015, 272: 309
[10]	Ratti M, Leuvrey D, Mathon M H, et al. Influence of titanium on nano-cluster (Y, Ti, O) stability in ODS ferritic materials [J]. J. Nucl. Mater., 2009, 386-388: 540
[11]	Zhang J R, Li Y F, Bao F Y, et al. Study on the formation mechanism of Y-Ti-O oxides during mechanical milling and annealing treatment [J]. Adv. Powder Technol., 2021, 32(2): 582
[12]	Peng Y Y, Yu L M, Liu Y C, et al. Microstructures and tensile properties of an austenitic ODS heat resistance steel [J]. Mater. Sci. Eng., 2019, 767A: 138419
[13]	Singh R, Prakash U, Kumar D, et al. Nano oxide particles in 18Cr oxide dispersion strengthened (ODS) steels with high yttria contents [J]. Mater. Charact., 2022, 189: 111936
[14]	Courtin L, Urvoy S, Bossu D, et al. Comparison of 15Cr-15Ni austenitic steel cladding tubes obtained by HPTR Cold Pilgering or by cold drawing [J]. Key Eng. Mater., 2015, 651-653: 38
[15]	Zhao R L, Jia H D, Yin C X, et al. Effects of cold rolling and heat treatment on microstructure and mechanical properties of 15Cr-15Ni ODS austenitic steel [J]. Mater. Today Commun., 2023, 37: 106941
[16]	Yan F Z, Li J, Xiong L Y, et al. Effect of explosive compaction on microstructure of ODS FeCrAl alloy fabricated by oxidation method [J]. Mater. Res. Express, 2021, 8: 046504
[17]	Chen C L, Zeng Y. Influence of Ti content on synthesis and characteristics of W-Ti ODS alloy [J]. J. Nucl. Mater., 2016, 469: 1
[18]	London A J, Santra S, Amirthapandian S, et al. Effect of Ti and Cr on dispersion, structure and composition of oxide nano-particles in model ODS alloys [J]. Acta Mater., 2015, 97: 223
[19]	Ukai S, Ohtsuka S. Nano-mesoscopic structure control in 9Cr-ODS ferritic steels [J]. Energy Mater., 2007, 2: 26
[20]	Chinnappan R. Thermodynamic stability of oxide phases of Fe-Cr based ODS steels via quantum mechanical calculations [J]. Calphad, 2014, 45: 188
[21]	Fu C L, Krčmar M, Painter G S, et al. Vacancy mechanism of high oxygen solubility and nucleation of stable oxygen-enriched clusters in Fe [J]. Phys. Rev. Lett., 2007, 99: 225502
[22]	Mao X D, Oh K H, Kang S H, et al. On the coherency of Y₂Ti₂O₇ particles with austenitic matrix of oxide dispersion strengthened steel [J]. Acta Mater., 2015, 89: 141
[23]	Oono N, Tang Q X, Ukai S. Oxide particle refinement in Ni-based ODS alloy [J]. Mater. Sci. Eng., 2016, 649A: 250
[24]	Mao X D, Kang S H, Kim T K, et al. Microstructure and mechanical properties of ultrafine-grained austenitic oxide dispersion strengthened steel [J]. Metall. Mater. Trans., 2016, 47A(11): 5334
[25]	Tang Q X, Hoshino T, Ukai S, et al. Refinement of oxide particles by addition of Hf in Ni-0.5 mass%Al-1 mass%Y₂O₃ alloys [J]. Mater. Trans., 2010, 51(11): 2019
[26]	Yang T X, Dou P, Li Z X, et al. Effects of Hf and/or Ti addition on the morphology, crystal, and metal/oxide interface structures of nanoparticles in FeCrAl-ODS steels [J]. Vacuum, 2024, 228: 113507

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