Low-Temperature Fatigue Crack Propagation Behavior of Bainitic Rail Steel

doi:10.11900/0412.1961.2024.00383

Acta Metall Sin

2026, Vol. 62

Issue (9): 1541-1552 DOI: 10.11900/0412.1961.2024.00383

Research paper

Current Issue | Archive | Adv Search

Low-Temperature Fatigue Crack Propagation Behavior of Bainitic Rail Steel

LIU Rong, GAO Guhui(

), GUI Xiaolu, BAI Bingzhe

School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China

Cite this article:

LIU Rong, GAO Guhui, GUI Xiaolu, BAI Bingzhe. Low-Temperature Fatigue Crack Propagation Behavior of Bainitic Rail Steel. Acta Metall Sin, 2026, 62(9): 1541-1552.

Download:

HTML

PDF(6207KB)
Export: BibTeX | EndNote (RIS)

Abstract

Bainitic rail steels have been extensively studied as a solution to the considerable fatigue and wear issues experienced with conventional pearlitic rails. With railway constructions in high-cold regions, the effect of low temperatures on the fatigue performance of railways has garnered considerable attention. Despite several studies on the room-temperature fatigue performance of high-strength steels, the effect of the microstructure, particularly retained austenite (RA), on the low-temperature fatigue crack growth behavior in bainitic rail steels remains unclear. This study examined the low-temperature fatigue crack propagation behavior of U20Mn2SiCrNiMo (U20Mn) bainitic rail steel subjected to hot rolling and air cooling. The microstructure of the bainitic rail steel was characterized employing SEM, TEM, EBSD, and XRD. The conventional mechanical properties and fatigue crack propagation rate (da / dN; where a is the crack length and N is the number of stress cycles) were determined at room temperature (20-25 ^oC) and -40 ^oC. The results demonstrated that the U20Mn bainitic rail steel was primarily composed of a granular bainite/martensite multiphase structure, with approximately 10% (volume fraction) RA. A decrease in the experimental temperature increased the tensile and yield strengths of the U20Mn rail steel; however, its impact toughness decreased. The da / dNvs stress intensity factor (ΔK) curves for U20Mn rail steel at room temperature and -40 ^oC indicated that the fatigue crack propagation rate reduced at low temperatures within the ΔK range of 8.0-18.0 MPa·m^1/2. However, an examination of the fatigue fracture surface revealed a transition from ductile to brittle fractures at -40 ^oC. This indicates that the combined effects of the increased strength, decreased toughness, and changes in the stability of RA at low temperatures are the underlying factors responsible for the variation in the low-temperature fatigue crack propagation rate of bainitic rail steel.

Key words: bainite rail steel low temperature fatigue crack propagation microstructure retained austenite

Received: 12 November 2024

ZTFLH:

TG142.1

Fund: National Key Research and Development Program of China(2021YFB3703500)

Corresponding Authors: GAO Guhui, professor, Tel: (010)51685495, E-mail: gaogh@bjtu.edu.cn

	Service

	E-mail this article
	Add to citation manager
	E-mail Alert
	RSS
	（）
	Articles by authors
	LIU Rong
	GAO Guhui
	GUI Xiaolu
	BAI Bingzhe

URL:

https://www.ams.org.cn/EN/10.11900/0412.1961.2024.00383 OR https://www.ams.org.cn/EN/Y2026/V62/I9/1541

Fig.1 Schematic of sampling positions for mechanical property testing (RD—rolling direction, ND—normal direction, TD—transverse direction)

Fig.2 Schematic of compact tensile (CT) specimen for fatigue crack growth rate test (unit: mm)

Fig.3 SEM and TEM observations of base microstructure of bainitic rail steel
(a) SEM image of base material (GB—granular bainite, LB—lath bainite, M/A—martensite/austenite)
(b) phase map of base material represented by EBSD
(c) TEM image showing the blocky M/A island and the twinning martensite (TM) (Inset shows locally enlarged image)
(d) TEM image showing the film-like retained austenite (RA)
(e, f) TEM bright field image (e) and TEM dark field image and SAED pattern (inset) (f) of blocky RA

Table 1 Mechanical properties of bainitic rail steel at room temperature (RT) and -40 ^oC

Fig.4 Engineering stress-strain curves of bainitic rail steel at RT and -40 ^oC

Fig.5 Changes of A_kv with test temperature for bainitic rail steel

Fig.6 Low (a, c) and locally high (b, d) magnified SEM images showing the impact fracture morphologies of bainitic rail steel tested at RT (a, b) and -40 ^oC (c, d)

Fig.7 da / dN-ΔK (fatigue crack propagation rate (da / dN) versus stress intensity factor range (ΔK)) curves of bainitic rail steel at RT and -40 ^oC (The constant m represents the slope of the fitted line)

Table 2 Paris equations for da / dN of bainitic rail steel at different temperatures

Fig.8 SEM images showing the fatigue fracture surface morphologies of bainitic rail steel tested under various ΔK at RT
(a) ΔK = 8.0 MPa·m^1/2 (b) ΔK = 10.0 MPa·m^1/2
(c-f) ΔK = 20.0 MPa·m^1/2 (Figs.8d and f show the locally enlarged images of Figs.8c and e, respectively)

Fig.9 SEM images showing the fatigue fracture surface morphologies of bainitic rail steel tested under various ΔK at -40 ^oC (BF—bainitic ferrite, PAGB—prior austenite grain boundary)
(a, b) ΔK = 9.0 MPa·m^1/2 (c, d) ΔK = 13.5 MPa·m^1/2
(e) ΔK = 16.5 MPa·m^1/2 (f) ΔK = 18.0 MPa·m^1/2
(g, h) etched fracture surface morphologies, where ΔK = 16.0-18.0 MPa·m^1/2

Fig.10 Fatigue crack propagation paths of bainitic rail steel tested under ΔK = 8.0-9.0 MPa·m^1/2 (a, b) and ΔK = 13.0-15.0 MPa·m^1/2 (c, d) at room temperature (The fatigue crack propagates through the M/A island ① and extends along the boundaries of the M/A island ② in Fig.10a)

Fig.11 Fatigue crack propagation paths of bainitic rail steel tested under various ΔK at -40 ^oC
(a, b) SEM (a) and EBSD (b) images under ΔK = 10.0 MPa·m^1/2
(c, d) grain reconstructions of square areas I (c) and II (d) in Fig.11b
(e, f) SEM images under ΔK = 17.0 MPa·m^1/2

Fig.12 Changes of the volume fraction of RA (f) with true strain (ε) for bainitic rail steel tested at different temperatures

Fig.13 Instantaneous work hardening curves for bainitic rail steel tested at RT and -40 ^oC

Fig.14 Percentages of phase transformation of RA near the fracture surface of bainitic rail steel in response to variations in ΔK

Fig.15 Schematic showing the influence of temperature on the radius of cyclic plastic zone (R_CPZ) and radius of transformation-induced plasticity zone (R_TRIP) (σ—stress)

[1]	Sakai T, Sato Y, Oguma N. Characteristic S-N properties of high-carbon chromium-bearing steel under axial loading in long-life fatigue [J]. Fatigue Fract. Eng. Mater. Struct., 2002, 25: 765 doi: 10.1046/j.1460-2695.2002.00574.x
[2]	Shiozawa K, Lu L. Very high-cycle fatigue behaviour of shot-peened high carbon-chromium bearing steel [J]. Fatigue Fract. Eng. Mater. Struct., 2002, 25: 813 doi: 10.1046/j.1460-2695.2002.00567.x
[3]	Gao G H, Liu R, Fan Y S, et al. Mechanism of subsurface microstructural fatigue crack initiation during high and very-high cycle fatigue of advanced bainitic steels [J]. J. Mater. Sci. Technol., 2022, 108: 142 doi: 10.1016/j.jmst.2021.08.060
[4]	Ma L, Guo J, Liu Q Y, et al. Fatigue crack growth and damage characteristics of high-speed rail at low ambient temperature [J]. Eng. Failure Anal., 2017, 82: 802 doi: 10.1016/j.engfailanal.2017.07.026
[5]	Fang X Y, Cai Z B, Wang J G, et al. Evaluation of temperature-sensitive fatigue crack propagation of a high-speed railway wheel rim material [J]. Fatigue Fract. Eng. Mater. Struct., 2019, 42: 1815 doi: 10.1111/ffe.v42.8
[6]	Shen M X, Qin Y F, Ji D H, et al. Role of ambient temperature in the adhesion and damage characteristics of wheel/rail interface during rolling-sliding contact [J]. Wear, 2022, 506-507: 204458 doi: 10.1016/j.wear.2022.204458
[7]	Zhou L, Wang W J, Hu Y, et al. Study on the wear and damage behaviors of hypereutectoid rail steel in low temperature environment [J]. Wear, 2020, 456-457: 203365 doi: 10.1016/j.wear.2020.203365
[8]	Rackwitz J, Yu Q, Yang Y, et al. Effects of cryogenic temperature and grain size on fatigue-crack propagation in the medium-entropy CrCoNi alloy [J]. Acta Mater., 2020, 200: 351 doi: 10.1016/j.actamat.2020.09.021
[9]	Fan Y S, Gui X L, Liu M, et al. Effect of microstructure on wear and rolling contact fatigue behaviors of Bainitic/Martensitic rail steels [J]. Wear, 2022, 508-509: 204474 doi: 10.1016/j.wear.2022.204474
[10]	Yokoyama H, Mitao S, Yamamoto S, et al. High strength bainitic steel rails for heavy haul railways with superior damage resistance [J]. Nkk Tech. Rev., 2001, (84): 44
[11]	Hajizad O, Kumar A, Li Z L, et al. Influence of microstructure on mechanical properties of bainitic steels in railway applications [J]. Metals, 2019, 9: 778. doi: 10.3390/met9070778
[12]	Bhadeshia H K D H. High performance bainitic steels [J]. Mater. Sci. Forum, 2005, 500-501: 63 doi: 10.4028/www.scientific.net/MSF.500-501
[13]	Gui X L, Gao G H, Guo H R, et al. Effect of bainitic transformation during BQ&P process on the mechanical properties in an ultrahigh strength Mn-Si-Cr-C steel [J]. Mater. Sci. Eng., 2017, A684: 598
[14]	Gao G H, Liu R, Wang K, et al. Role of retained austenite with different morphologies on sub-surface fatigue crack initiation in advanced bainitic steels [J]. Scr. Mater., 2020, 184: 12 doi: 10.1016/j.scriptamat.2020.03.036
[15]	Guo H R, Gao G H, Gui X L, et al. Structure-property relation in a quenched-partitioned low alloy steel involving bainite transformation [J]. Mater. Sci. Eng., 2016, A667: 224.
[16]	Cheng X, Gao G H, Liu R, et al. Development of air-cooled carbide-free bainite/martensite multiphase steel: Transformation kinetics, microstructure, and mechanical properties [J]. Steel Res. Int., 2024, 95: 2300619 doi: 10.1002/srin.v95.3
[17]	Gao G H, Gui X L, An B F, et al. Effect of finish cooling temperature on microstructure and low temperature toughness of Mn-series ultra-low carbon high strength low alloyed steel [J]. Acta Metall. Sin., 2015, 51: 21 doi: 10.11900/0412.1961.2014.00329
	高古辉, 桂晓露, 安佰锋等. 冷温度对Mn系超低碳HSLA钢组织及低温韧性的影响 [J]. 金属学报, 2015, 51: 21 doi: 10.11900/0412.1961.2014.00329
[18]	Wang B S, Chen N N, Cai Y, et al. Effect of crystallographic features on low-temperature fatigue ductile-to-brittle transition for simulated coarse-grained heat-affected zone of bainite steel weld [J]. Int. J. Fatigue, 2023, 170: 107523 doi: 10.1016/j.ijfatigue.2023.107523
[19]	Laird C. The influence of metallurgical structure on the mechanisms of fatigue crack propagation [A]. Fatigue Crack Propagation [M]. Philadelphia: American Society for Testing and Materials, 1967: 131
[20]	Zhao W D, Feng G Q, Ren H L, et al. Temperature-dependent characteristics of DH36 steel fatigue crack propagation [J]. Fatigue Fract. Eng. Mater. Struct., 2020, 43: 617 doi: 10.1111/ffe.v43.3
[21]	Jiang C P, Ma H C, Chen Y N, et al. Crack propagation behavior of dual-phase steel at low temperature [J]. Int. J. Fatigue, 2022, 155: 106633 doi: 10.1016/j.ijfatigue.2021.106633
[22]	Gao G H, Wang K, Su H, et al. The potential of mechanical twinning in ultrafine retained austenite to enhance high cycle fatigue property of advanced Bainitic steels [J]. Int. J. Fatigue, 2020, 139: 105804 doi: 10.1016/j.ijfatigue.2020.105804
[23]	Sugimoto K I, Kobayashi M, Hashimoto S I. Ductility and strain-induced transformation in a high-strength transformation-induced plasticity-aided dual-phase steel [J]. Metall. Trans, 1992, 23A: 3085
[24]	Zhou S, Zhang K, Wang Y, et al. High strength-elongation product of Nb-microalloyed low-carbon steel by a novel quenching-partitioning-tempering process [J]. Mater. Sci. Eng., 2011, A528: 8006
[25]	Curtze S, Kuokkala V T, Hokka M, et al. Deformation behavior of TRIP and DP steels in tension at different temperatures over a wide range of strain rates [J]. Mater. Sci. Eng., 2009, A507: 124
[26]	Sahu V K, Anil Kumar J K S, Mohanty J R, et al. Effect of low‐temperature over load on fatigue crack growth retardation and prediction of post overload fatigue life [J]. Aerosp. Sci. Technol., 2014, 33: 100 doi: 10.1016/j.ast.2014.01.005
[27]	Wang B S, Chen N N, Cai Y, et al. Low-temperature fatigue ductile-to-brittle transition behavior and mechanism for simulated coarse-grained heat-affected zone of a high-strength low-alloy bainite steel [J]. J. Mech. Eng., 2024, 60: 271
	王博士, 陈楠楠, 蔡艳等. 低合金贝氏体高强钢模拟焊接粗晶热影响区低温疲劳韧脆转变行为及机制 [J]. 机械工程学报, 2024, 60: 271
[28]	Yang M, Zhong Y, Liang Y L. Effect of hierarchical microstructures of lath Martensite on the transitional behavior of fatigue crack growth rate [J]. Met. Mater. Int., 2018, 24: 970 doi: 10.1007/s12540-018-0117-4
[29]	Burda I, Zweiacker K, Arabi-Hashemi A, et al. Fatigue crack propagation behavior of a micro-bainitic TRIP steel [J]. Mater. Sci. Eng., 2022, A840: 142898
[30]	Agnani M, Findley K O, Thompson S W. Effects of retained austenite and martensite microstructure on fatigue crack propagation in quenched and tempered high carbon steels [J]. Int. J. Fatigue, 2024, 188: 108529 doi: 10.1016/j.ijfatigue.2024.108529
[31]	Hilditch T B, Timokhina I B, Robertson L T, et al. Cyclic deformation of advanced high-strength steels: Mechanical behavior and microstructural analysis [J]. Metall. Mater. Trans., 2009, 40A: 342
[32]	Mayer H R, Stanzl-Tschegg S E, Sawaki Y, et al. Influence of transformation-induced crack closure on slow fatigue crack growth under variable amplitude loading [J]. Fatigue Fract. Eng. Mater. Struct., 1995, 18: 935 doi: 10.1111/ffe.1995.18.issue-9
[33]	Elber W. The significance of fatigue crack closure [A]. Damage Tolerance in Aircraft Structures [M]. Philadelphia: ASTM, 1971: 230
[34]	Cheng X, Petrov R, Zhao L, et al. Fatigue crack growth in TRIP steel under positive R-ratios [J]. Eng. Fract. Mech., 2008, 75: 739 doi: 10.1016/j.engfracmech.2007.01.019
[35]	Wang X G, Liu C H, Sun B H, et al. The dual role of martensitic transformation in fatigue crack growth [J]. Proc. Natl. Acad. Sci. USA, 2022, 119: e2110139119 doi: 10.1073/pnas.2110139119

[1]	LIU Zetian, LU Weizhao, XU Xinyu, LIU Xu, ZHANG Shaoyou, WANG Huiyuan. Effect of Homogenization Temperature on the Microstructure and Mechanical Properties of 3003 Aluminum Alloys[J]. 金属学报, 2026, 62(9): 1503-1516.
[2]	SU Yiyun, HAO Xiaohu, LI Shuhua, CUI Zeqin, YAN Dejun, LI Weiguo. Effect of Transient Heat Treatment on the Interfacial Microstructure and Bonding Properties of Titanium/Steel Transit Joint[J]. 金属学报, 2026, 62(9): 1528-1540.
[3]	LIU Yang, SUN Jian, LU Shanping. Effect of Mo Content on the Microstructure and Mechanical Properties of 1000 MPa Grade High-Strength Steel Weld Metal[J]. 金属学报, 2026, 62(9): 1553-1565.
[4]	WEI Zichao, WU Huaduo, HUANG Guangfa, LE Jianwen, LV Weijie, HAN Yuanfei. Design and Fabrication of Bamboo-Fiber-Like TiB/Ti Composites with Strengthening and Toughening Mechanisms[J]. 金属学报, 2026, 62(9): 1581-1590.
[5]	DIAO Shengxuan, XIAO Jinyong, CHEN Yongbao, SHAN Kangzhong, YANG Jie. Multi-Scale Fatigue Crack Propagation Prediction Based on the Dual Drive of Random Forest Algorithm and Data Augmentation Strategy[J]. 金属学报, 2026, 62(9): 1606-1614.
[6]	YANG Kun, GUO Qingwei, LI Chao, ZHANG Gaolong, ZHAO Yuhong, HOU Hua. Dynamic Mechanical Response and Spallation Behavior of 60 Steel Under Shock Loading[J]. 金属学报, 2026, 62(8): 1405-1416.
[7]	YIN Jiannian, MA Yingjie, YANG Rui, LEI Jiafeng, QI Min, ZHOU Li. Hot Deformation Behavior and Hot Processing Map Construction of the Ti551 Alloy[J]. 金属学报, 2026, 62(8): 1427-1442.
[8]	YANG He, HOU Ziyong, HU Xingyi, CHENG Jinjun, WANG Yaru, FAN Guohua, HUANG Xiaoxu. Research Progress and Trends in Characterization Techniques for Ultra-High-Strength and Ultra-Fine Stainless Steel Wires: A Perspective Review[J]. 金属学报, 2026, 62(7): 1189-1206.
[9]	LI Ruixue, ZHOU Chenxi, YANG Huimin, YONG Xingyue, LIU Jingjun. Microstructural Evolution and Dynamic Failure Mechanism of B10 Cu-Ni Alloy Under Multiple Stress Coupling in Flowing Seawater[J]. 金属学报, 2026, 62(7): 1273-1287.
[10]	WANG Wei, ZHANG Yubo, ZHAO Yan, WANG Tongmin, LI Tingju. Influences of High-Entropy Alloy Particles on the Microstructure and Mechanical Properties of Selective Laser Melted Al12Si Alloy During Solution Treatment[J]. 金属学报, 2026, 62(6): 1009-1020.
[11]	WANG Bin, ZHAO Peng, LIU Jiawei, ZHANG Chunbo, QIN Zhiwei, DONG Honggang, LI Peng. Effect of Heat Treatment on Microstructural Evolution and Mechanical Properties of Inertial Friction Welded Joints for FGH96 Superalloy[J]. 金属学报, 2026, 62(6): 1043-1058.
[12]	WANG Mingfei, TAO Meiyue, GONG Chen, PENG Bo, LI Tingju, JIE Jinchuan. Microstructural Evolution and Strengthening Mechanisms of Cu-Ni-Si/1010 Steel Bimetallic Composites via Direct Annealing and Cold Rolling + Annealing[J]. 金属学报, 2026, 62(6): 1091-1104.
[13]	ZHU Siying, YI Min, GUO Wanlin. Topological Properties and Characteristics of Grain Boundary Structure in Metallic Materials[J]. 金属学报, 2026, 62(5): 705-720.
[14]	XIE Hongji, LI Jiarong, LUO Yushi, ZHENG Sujie, LUO Kailun. Effect of Solidification Conditions on Microstructure Evolution in DD6 Single-Crystal Superalloy[J]. 金属学报, 2026, 62(4): 550-560.
[15]	WANG Jianfeng, XU Zhenmu, LIU Zhan, GAO Zhuanni, ZHAN Xiaohong. Effect of Ultrasonic Vibration on the Microstructure and Strengthening Mechanism of Narrow Gap Laser Welding of TC4 Titanium Alloy[J]. 金属学报, 2026, 62(3): 406-420.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Shared

Discussed