Mechanism of Fatigue Crack Initiation Induced by Complex Inclusions in Bainite-Martensite Dual-phase Steel

doi:10.11901/1005.3093.2026.114

Chinese Journal of Materials Research

2026, Vol. 40

Issue (7): 519-527 DOI: 10.11901/1005.3093.2026.114

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Mechanism of Fatigue Crack Initiation Induced by Complex Inclusions in Bainite-Martensite Dual-phase Steel

XIE Zhenjun¹^,², ZHU Yankun², ZHAO Zhenkai², LU Yandi²^,⁴, ZHOU Xianghai², CAO Ming³(

), ZHANG Peng²(

), ZHANG Zhefeng¹^,²(

)

^1.Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450003, China
^2.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
^3.Tianjin Heavy Industries Research & Development Co., Ltd., Tianjin 300457, China
^4.School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China

Cite this article:

XIE Zhenjun, ZHU Yankun, ZHAO Zhenkai, LU Yandi, ZHOU Xianghai, CAO Ming, ZHANG Peng, ZHANG Zhefeng. Mechanism of Fatigue Crack Initiation Induced by Complex Inclusions in Bainite-Martensite Dual-phase Steel. Chinese Journal of Materials Research, 2026, 40(7): 519-527.

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Abstract

The high-cycle fatigue (HCF) damage behavior of a bainite-martensite dual-phase steel was studied in terms of the relevant mechanism of cyclic softening emerged by cyclic tension-compression loading. It is found that, inclusions in the steel are predominantly complex inclusions consisting of hard oxide cores encapsulated by MnS shells, from which fatigue cracks preferentially initiate. Statistical analysis reveals that, under a cyclic loading condition with stress ratio of R = -1, the fatigue lives of most specimens are located into two distinct regimes, approximately 10⁵ and 10⁷ cycles, exhibiting a characteristic of pronounced bimodal distribution. Fractographic analysis combined with finite element method (FEM) simulations demonstrates that significant stress concentration arises at the interface between the MnS shell and the steel matrix. Such interfacial regions, particularly those located near the specimen surface, are more susceptible to fatigue crack initiation. Consequently, both the structural characteristics and spatial distribution of large non-metallic inclusions play a dominant role in the bimodal fatigue life behavior of this material.

Key words: metallic materials bainite-martensite steel high-cycle fatigue non-metallic inclusions finite element method

Received: 29 January 2026

ZTFLH:

TG142.1

Fund: National Natural Science Foundation of China(52371123)

Corresponding Authors: ZHANG Zhefeng, Tel: (024)83978779, E-mail: zhfzhang@imr.ac.cn;
ZHANG Peng, Tel: (024)83978870, E-mail: pengzhang@imr.ac.cn;
CAO Ming, Tel: 18522810515, E-mail: caoming8118@163.com

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	Articles by authors
	XIE Zhenjun
	ZHU Yankun
	ZHAO Zhenkai
	LU Yandi
	ZHOU Xianghai
	CAO Ming
	ZHANG Peng
	ZHANG Zhefeng

URL:

https://www.cjmr.org/EN/10.11901/1005.3093.2026.114 OR https://www.cjmr.org/EN/Y2026/V40/I7/519

Fig.1 Schematic diagrams of specimen dimensions for tensile testing (a), and high-cycle fatigue testing (b)

Fig.2 Finite element mesh surrounding the inclusion (a) surface inclusion, (b) interior inclusion

Fig.3 Microstructure of the experimental steel (a) OM, (b) SEM

Fig.4 Non-metallic inclusions in the experimental steel and corresponding EDS mapping results (a) SEM micrograph, (b) Al, (c) Mg, (d) S, (e) Mn

Fig.5 Engineering stress-strain curves of the experimental steel

Fig.6 Staircase method diagram for fatigue strength (a) and S-N curve (b) of the experimental steel

Specimen	σ_a / MPa	N_f	$a r e a$ / μm	Inclusion location	Shell composition	Core composition
1	560	639427	57.28	Surface	MnS	Al₂O₃ + MgO
2	580	2924716	80.29	Interior	MnS	Al₂O₃ + MgO
3	600	7877568	55.23	Surface	MnS + MgO	Al₂O₃ + MgO
4	600	9204356	46.98	Interior	MnS	Al₂O₃ + MgO
5	620	6810867	58.52	Interior	MnS	Al₂O₃ + MgO
6	620	9604958	42.80	Interior	MnS	Al₂O₃ + MgO
7	620	104205	36.50	Surface	MnS	Al₂O₃ + MgO
8	640	102635	36.70	Surface	MnS	Al₂O₃ + MgO
9	640	8588689	47.29	Interior	MnS	Al₂O₃ + MgO
10	640	1229512	71.52	Interior	MnS	Al₂O₃ + MgO
11	640	171627	35.46	Surface	MnS	Al₂O₃ + MgO
12	660	95867	36.78	Surface	MnS	Al₂O₃ + MgO
13	660	124227	32.90	Surface	MnS	Al₂O₃ + MgO
14	660	94503	20.46	Surface	MnS	Al₂O₃ + MgO
15	660	117826	27.85	Surface	MnS	Al₂O₃ + MgO
16	680	157013	28.90	Surface	MnS	Al₂O₃ + MgO
17	680	105946	27.38	Surface	MnS	Al₂O₃ + MgO
18	680	66951	49.04	Surface	MnS	Al₂O₃ + MgO
19	680	77065	31.35	Surface	MnS	Al₂O₃ + MgO
20	700	72432	26.40	Surface	MnS	Al₂O₃ + MgO
21	700	104337	24.78	Surface	MnS	Al₂O₃ + MgO
22	700	50186	28.66	Surface	MnS	Al₂O₃ + MgO

Table 1 Fatigue life, fractographic features, and inclusion characteristics of the experimental steels

Fig.7 SEM micrographs of the fracture surface showing surface inclusion-induced crack initiation (σ_a = 560 MPa, N_f = 639427) (a) macroscopic fracture morphology, (b) morphology of the inclusion at the crack initiation site, (c) EDS analysis result of the inclusion

Fig.8 SEM micrographs of the fracture surface showing internal inclusion-induced crack initiation (σ_a = 580 MPa, N_f = 2924716) (a) macroscopic fracture morphology, (b) morphology of the inclusion at the crack initiation site, (c) EDS analysis result of the inclusion

Table 2 Mechanical parameters of inclusions and the steel matrix

Fig.9 Contours of equivalent stress surrounding MnS inclusions (a) near-surface inclusion, (b) internal inclusion

Fig.10 Statistical results of inclusion locations. Int-inc: internal inclusion-induced crack initiation, sur-inc: surface inclusion-induced crack initiation

Fig.11 SEM micrographs of the fracture surface of the special specimen (σ_a = 600 MPa, N_f = 7877568) (a) non-metallic inclusion at the crack initiation site, (b-g) EDS mapping results of Fe, O, Al, S, Mg, and Mn, respectively

[1]	Motte R, De Waele W. An overview of estimations for the high-cycle fatigue strength of conventionally manufactured steels based on other mechanical properties [J]. Metals, 2024, 14(1): 85 doi: 10.3390/met14010085
[2]	Findlay S J, Harrison N D. Why aircraft fail [J]. Mater. Today, 2002, 5(11): 18
[3]	Giorgetti A, Millefanti U, La Battaglia V, et al. Investigations of fatigue damage in a nitriding low-carbon bainitic steel for high-performance crankshaft [J]. Metals, 2022, 12(12): 2052 doi: 10.3390/met12122052
[4]	Kruzic J J. Predicting fatigue failures [J]. Science, 2009, 325(5937): 156 doi: 10.1126/science.1173432 pmid: 19589990
[5]	Lankford J. Inclusion-matrix debonding and fatigue crack initiation in low alloy steel [J]. Int. J. Fract., 1976, 12(1): 155 doi: 10.1007/BF00036019
[6]	Lankford J. (E) effect of oxide inclusions on fatigue failure [J]. Int. Mater. Rev., 1977, 22(1): 221
[7]	Xue W, Li Z L, Xiao K, et al. Initial microzonal corrosion mechanism of inclusions associated with the precipitated (Ti, Nb)N phase of Sb-containing weathering steel [J]. Corros. Sci., 2020, 163: 108232 doi: 10.1016/j.corsci.2019.108232
[8]	Cui Y, Zhang C D, Yu F, et al. Influence of large carbides on rotating bending fatigue of GCr4Mo4V steel [J]. Heat Treat. Met., 2023, 48: 50 doi: 10.13251/j.issn.0254-6051.2023.02.008
	崔毅, 张彩东, 俞峰等. 大颗粒碳化物对GCr4Mo4V钢旋转弯曲疲劳的影响 [J]. 金属热处理, 2023, 48: 50
[9]	Lü Y, Jia Y H, Zhang X F, et al. Literature review on inclusions in steel [J]. Metall. Anal., 2025, 45: 1
	吕勇, 贾云海, 张晓芬等. 钢中夹杂物的文献综述 [J]. 冶金分析, 2025, 45: 1
[10]	Wu H J, Xiao T L, Xu Y T, et al. Effect of rare earth cerium on inclusions and contact fatigue properties in high-carbon chromium bearing steel [J]. Metall. Mater. Trans., 2026, 57B(1) : 65
[11]	Hao C L, Wen J, Liu Z Y, et al. Effect of rare-earth elements on fatigue properties of spring steel [J]. J. Mater. Eng. Perform., 2025, 34(1): 596 doi: 10.1007/s11665-023-09063-1
[12]	Guo J B, Shen C, Lu Q. Improvement of the MnS composite inclusions on the fatigue behaviour of wheel steel [J]. Steelmaking, 2024, 40: 104
	郭俊波, 沈昶, 陆强. 硫化锰复合夹杂物对车轮钢疲劳性能的改善 [J]. 炼钢, 2024, 40: 104
[13]	Li S J, Ren X C, Gao K W, et al. Effect of heat treatment on morphology and distribution of inclusions in wheel steels [J]. Trans. Mater. Heat Treat., 2011, 32: 48
	李胜军, 任学冲, 高克玮等. 热处理对车轮钢中夹杂物的形态和分布的影响 [J]. 材料热处理学报, 2011, 32: 48
[14]	Yu Y H, Pan T, Yin J C, et al. Effect of sulfur contents on properties and inclusions in high speed wheel steels [J]. Iron Steel, 2013, 48: 57
	余音宏, 潘涛, 尹建成等. S含量对高速车轮钢性能和夹杂物的影响 [J]. 钢铁, 2013, 48: 57
[15]	Ma Y, Su H, Pan T, et al. Study of complex ductile inclusions controlling in medium-high carbon steels [J]. Acta Metall. Sin., 2012, 48: 1321 doi: 10.3724/SP.J.1037.2012.00225
	马跃, 苏航, 潘涛等. 中高碳钢中复合延性夹杂物控制研究 [J]. 金属学报, 2012, 48: 1321
[16]	Xu X N, Tian Y, Ye Q B, et al. The significant impact of the characteristics of granular structure and granular bainite on the mechanisms contributing to strength-ductility combination [J]. J. Mater. Eng. Perform., 2021, 30(10): 7479 doi: 10.1007/s11665-021-05887-x
[17]	Li Z D, Zhou S T, Yang C F, et al. High/very high cycle fatigue behaviors of medium carbon pearlitic wheel steels and the effects of microstructure and non-metallic inclusions [J]. Mater. Sci. Eng., 2019, 764A: 138208
[18]	Jiang Q Q, Sun C Q, Liu X L, et al. Very-high-cycle fatigue behavior of a structural steel with and without induced surface defects [J]. Int. J. Fatigue, 2016, 93: 352 doi: 10.1016/j.ijfatigue.2016.05.032
[19]	Song Q Y, Sun C Q. Mechanism of crack initiation and early growth of high strength steels in very high cycle fatigue regime [J]. Mater. Sci. Eng., 2020, 771A: 138648
[20]	Murakam Y, Nomoto T, Ueda T. Factors influencing the mechanism of superlong fatigue failure in steels [J]. Fatigue Fract. Eng. Mater. Struct., 1999, 22(7): 581 doi: 10.1046/j.1460-2695.1999.00187.x
[21]	Murakami Y, Yokoyama N N, Nagata J. Mechanism of fatigue failure in ultralong life regime [J]. Fatigue Fract. Eng. Mater. Struct., 2002, 25(8-9): 735 doi: 10.1046/j.1460-2695.2002.00576.x
[22]	Zhang H J, Yu F, Li S X, et al. Fine granular area formation by damage-induced shear strain localization in very-high-cycle fatigue [J]. Fatigue Fract. Eng. Mater. Struct., 2021, 44(9): 2489 doi: 10.1111/ffe.v44.9
[23]	Zhu M L, Jin L, Xuan F Z. Fatigue life and mechanistic modeling of interior micro-defect induced cracking in high cycle and very high cycle regimes [J]. Acta Mater., 2018, 157: 259 doi: 10.1016/j.actamat.2018.07.036
[24]	Shiozawa K, Lu L, Ishihara S. S-N curve characteristics and subsurface crack initiation behaviour in ultra-long life fatigue of a high carbon-chromium bearing steel [J]. Fatigue Fract. Eng. Mater. Struct., 2001, 24(12): 781 doi: 10.1046/j.1460-2695.2001.00459.x
[25]	Shiozawa K, Morii Y, Nishino S, et al. Subsurface crack initiation and propagation mechanism in high-strength steel in a very high cycle fatigue regime [J]. Int. J. Fatigue, 2006, 28(11): 1521 doi: 10.1016/j.ijfatigue.2005.08.015
[26]	Ochi Y, Matsumura T, Masaki K, et al. High-cycle rotating bending fatigue property in very long-life regime of high-strength steels [J]. Fatigue Fract. Eng. Mater. Struct., 2002, 25(8-9): 823 doi: 10.1046/j.1460-2695.2002.00575.x
[27]	Zeng D F, Wang J, Lu L T, et al. Fatigue crack growth behavior of railway wheel steel modified by sulfides enveloping oxides inclusions [J]. Int. J. Fatigue, 2023, 175: 107811 doi: 10.1016/j.ijfatigue.2023.107811
[28]	Wu Z F, Che L D, Liu Z Y, et al. Effect of cooling process on microstructure and fracture toughness of as-cast advanced high strength steel [J]. Trans. Mater. Heat Treat., 2020, 41: 94
	吴战芳, 车立达, 刘振宇等. 冷却制度对铸态先进高强度钢组织及断裂韧性的影响 [J]. 材料热处理学报, 2020, 41: 94 doi: 10.13289/j.issn.1009-6264.2020-0120
[29]	Ju L Y, Gu S P, Tan M, et al. First principle calculation of non-metallic inclusions properties in steel [J]. China Metall., 2024, 34: 69
	琚立颖, 谷少鹏, 谭敏等. 钢中非金属夹杂物性质第一性原理计算 [J]. 中国冶金, 2024, 34: 69 doi: 10.13228/j.boyuan.issn1006-9356.20230594
[30]	Sabirov I, Kolednik O. The effect of inclusion size on the local conditions for void nucleation near a crack tip in a mild steel [J]. Scr. Mater., 2005, 53(12): 1373 doi: 10.1016/j.scriptamat.2005.08.027
[31]	Suresh S. Fatigue of Materials [M]. 2nd ed. Cambridge: Cambridge University Press, 1998: 213
[32]	Fan Y S, Gao G H, Xu X, et al. A fatigue life prediction approach to surface and interior inclusion induced high cycle and very-high cycle fatigue for bainite/martensite multiphase steel [J]. Int. J. Fatigue, 2025, 192: 108723 doi: 10.1016/j.ijfatigue.2024.108723
[33]	Hu D Y, Wang T, Ma Q H, et al. Effect of inclusions on low cycle fatigue lifetime in a powder metallurgy nickel-based superalloy FGH96 [J]. Int. J. Fatigue, 2019, 118: 237 doi: 10.1016/j.ijfatigue.2018.09.019

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