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3 pages, 178 KiB

Open AccessEditorial

Microstructure, Fatigue, Wear Properties of Steels

by Xiaoyan Long, Yu Zhang, Wei Liu, Zhen Zhang and Ranran Zhu

Coatings 2022, 12(12), 1818; https://doi.org/10.3390/coatings12121818 - 25 Nov 2022

Viewed by 985

Abstract

Green manufacturing is a hot topic in the manufacturing industry [...] Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

Research

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16 pages, 8399 KiB

Open AccessArticle

Microstructure and Corrosion Resistance of Quartz Sand-Modified Enamel-Coated Steel Plates

by Hao Cui, Fujian Tang, Bo Li and Zhibin Lin

Coatings 2023, 13(10), 1704; https://doi.org/10.3390/coatings13101704 - 28 Sep 2023

Cited by 1 | Viewed by 941

Abstract

Coating, as a corrosion protection measure, not only reduces the costs of repairs due to corrosion damage but also saves lives from injuries brought by corroded facilities or equipment. The corrosion behavior of quartz sand-modified enamel (QSME)-coated carbon steel plates was evaluated in [...] Read more.

Coating, as a corrosion protection measure, not only reduces the costs of repairs due to corrosion damage but also saves lives from injuries brought by corroded facilities or equipment. The corrosion behavior of quartz sand-modified enamel (QSME)-coated carbon steel plates was evaluated in a 3.5 wt.% NaCl solution for a period of 30 days using open circuit potential, electrochemical impedance spectroscopy (EIS), and linear polarization resistance. The enamel coating was made by firing enamel slurry to the steel plate at a temperature of around 840 °C. The effect of the size and content of quartz sand on the corrosion resistance is studied, considering four different contents (5 wt.%, 10 wt.%, 20 wt.%, and 30 wt.%) and two different particle sizes (0.38–0.83 mm and 0.83–1.70 mm). The microstructure and phase composition of QSME were characterized with a scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. SEM images show that the thickness of QSME coating ranges from 430 to 1424 µm depending on the size of quartz sand, and the quartz sand is completely embedded in the enamel matrix. The QSME coating increases the corrosion resistance of uncoated steel plates by approximately 1000 times. The corrosion performance of QSME-coated plates decreases with an increase in quartz sand content, while the effect of the quartz sand size on the corrosion behavior is not significant. The QSME coating can be used to prolong the service lives of civil infrastructures subjected to chloride attack. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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13 pages, 6131 KiB

Open AccessArticle

Study on the Influence of Pre-Formed Phase on Accelerating Bainitic Transformation

by Xiaoyan Long, Yu Zhang, Dongyun Sun, Dongxin Yin, Wei Liu, Zhen Zhang, Fucheng Zhang and Yanguo Li

Coatings 2023, 13(10), 1700; https://doi.org/10.3390/coatings13101700 - 27 Sep 2023

Viewed by 733

Abstract

Bainitic transformation goes through three stages: incubation period, nucleation, and growth. The long transformation time is not conducive to industrial production, which restricts its development. Therefore, research on accelerating bainitic transformation is based on the situation of energy saving and efficiency saving. The [...] Read more.

Bainitic transformation goes through three stages: incubation period, nucleation, and growth. The long transformation time is not conducive to industrial production, which restricts its development. Therefore, research on accelerating bainitic transformation is based on the situation of energy saving and efficiency saving. The methods to accelerate bainitic transformation include the control of alloy elements, heat treatment control, etc. This paper focuses on the influence of the pre-formed phase on the kinetics of accelerated bainite transformation. Combined with existing research and experiments, it clarifies the influence of pre-formed ferrite, pre-formed martensite, and precipitated second-phase particles on the kinetics of bainitic transformation. Moreover, it clarifies the characteristics of bainitic transformation in terms of microstructure characterization. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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17 pages, 4037 KiB

Open AccessArticle

Characterizations and Kinetic Modelling of Boride Layers on Bohler K190 Steel

by Peter Orihel, Peter Jurči and Mourad Keddam

Coatings 2023, 13(6), 1000; https://doi.org/10.3390/coatings13061000 - 28 May 2023

Cited by 2 | Viewed by 1273

Abstract

In this study, the Bohler K190 steel, manufactured by the powder metallurgy (PM) process, was subjected to the boronizing process. This thermochemical treatment was carried out in the range of 1173 to 1323 K, for 1–10 h. The scanning electron microscopy (SEM) was [...] Read more.

In this study, the Bohler K190 steel, manufactured by the powder metallurgy (PM) process, was subjected to the boronizing process. This thermochemical treatment was carried out in the range of 1173 to 1323 K, for 1–10 h. The scanning electron microscopy (SEM) was utilized for examining the morphology of layers’ interfaces with a dual-phase nature and measuring the layers’ thicknesses. The obtained boronized layers had a maximum thickness of 113 ± 4.5 µm. The X-ray diffraction analysis (XRD) confirmed the presence of FeB and Fe₂B layers. The energy dispersive spectroscopy (EDS) mapping and EDS point analysis were used to investigate the redistribution of chemical elements within the boronized layers and the transition zone. The values of Vickers microhardness of Fe₂B, FeB, and transition zone were estimated. Finally, the boron activation energies in FeB and Fe₂B were found to be 204.54 and 196.67 kJ·mol⁻¹ based on the integral method and compared to the literature results. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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20 pages, 7183 KiB

Open AccessArticle

Influence of Different Contact Conditions on Friction Properties of AISI 430 Steel Sheet with Deep Drawing Quality

by Valmir Dias Luiz, Anderson Júnior dos Santos, Marcelo Araújo Câmara and Paulo César de Matos Rodrigues

Coatings 2023, 13(4), 771; https://doi.org/10.3390/coatings13040771 - 14 Apr 2023

Cited by 5 | Viewed by 1329

Abstract

This article aims to investigate the influence of different contact conditions on the friction properties of an Nb-stabilized AISI 430 ferritic stainless-steel sheet with deep drawing quality. Three tribological tests were performed: pin-on-disk, bending under tension, and strip-tension test. Moreover, counter samples of [...] Read more.

This article aims to investigate the influence of different contact conditions on the friction properties of an Nb-stabilized AISI 430 ferritic stainless-steel sheet with deep drawing quality. Three tribological tests were performed: pin-on-disk, bending under tension, and strip-tension test. Moreover, counter samples of a hard metal (WC-12%Co) with surface finishes of 0.27 and 0.54 μm were used in the friction tests under dry and lubricated conditions. The influence of the texture and relative elongation of the strip on formability also were investigated. A comparative analysis of the results revealed that the coefficients of friction, wear, lubricant efficiency, and hardness measured below the wear surface indicated a strong dependence on surface roughness and the friction test type. The coefficients of friction obtained from the pin-on-disk test were higher than those obtained from the formability tests. In addition, the coefficient of friction increased with increasing relative elongation during the formability tests; it was higher in the bending-under-tension test than in the strip-tension test, mainly owing to the increasing strip surface roughness. The contact pressure during the formability tests was non-uniform during strip sliding under the tool. According to our results, for each friction condition in a specific area of the forming die, there is a value of the coefficient of friction, depending on the kinematic conditions. Therefore, the results can be used as input data to define design guidelines, improve productivity, and improve product quality from this steel sheet. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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10 pages, 2144 KiB

Open AccessCommunication

Buckling Characteristics of Different Cross-Sectioned LGFR-PP Stiffeners under Axial Compression

by Jin Nie, Wenbo Gao and Guibing Li

Coatings 2023, 13(4), 763; https://doi.org/10.3390/coatings13040763 - 12 Apr 2023

Viewed by 801

Abstract

Long glass fiber-reinforced polypropylene (LGFR-PP) composite structures with stiffeners are important substitutes for metal parts for vehicle lightweighting; a good understanding of the buckling characteristics of LGFR-PP stiffeners would provide an important reference for engineering design. The current work is therefore intended to [...] Read more.

Long glass fiber-reinforced polypropylene (LGFR-PP) composite structures with stiffeners are important substitutes for metal parts for vehicle lightweighting; a good understanding of the buckling characteristics of LGFR-PP stiffeners would provide an important reference for engineering design. The current work is therefore intended to study the buckling characteristics of different cross-sectioned LGFR-PP stiffeners under axial compression via experimental and theoretical analysis. Firstly, LGFR-PP stiffeners with semicircular, rectangular, and trapeziform cross-sections were compressed at the axial direction using a universal testing machine to obtain the buckling process data. Then, the elasticity stability theory modified according to the experimental results was derived to estimate the buckling resistance of LGFR-PP stiffeners in different designs. The test results showed that the LGFR-PP stiffeners possessed a flexible–torsional bulking instability mode under axial compression, the LGFR-PP stiffeners with a semicircular cross-section had higher compression buckling resistance, and the rectangular and trapeziform cross-sectioned stiffeners had better rigidity. The theoretical analysis showed that the modified elasticity stability theory could generally predict the buckling resistance of LGFR-PP stiffeners under axial compression. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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13 pages, 6483 KiB

Open AccessArticle

The Oxide Layer of 10Mn5 Medium Manganese Steel for Wear Protection in High-Temperature Friction during Hot Stamping

by Huan Teng, Yiwen Wang, Wurong Wang, Yangyang Zhao, Xicheng Wei and Hongshan Zhao

Coatings 2023, 13(3), 570; https://doi.org/10.3390/coatings13030570 - 7 Mar 2023

Viewed by 1214

Abstract

A custom-designed high-temperature sliding-on-sheet-strip (SOSS) tribo-tester was used to simulate the high-temperature friction process of 10Mn5 medium manganese steel bare plate under actual hot stamping conditions. To reveal its high-temperature friction mechanism in the hot forming process, the high-temperature friction behavior of 10Mn5 [...] Read more.

A custom-designed high-temperature sliding-on-sheet-strip (SOSS) tribo-tester was used to simulate the high-temperature friction process of 10Mn5 medium manganese steel bare plate under actual hot stamping conditions. To reveal its high-temperature friction mechanism in the hot forming process, the high-temperature friction behavior of 10Mn5 steel and 22MnB5 steel was compared. The scanning electron microscope (SEM), energy spectrum analyzer (EDS) and X-ray diffractometer (XRD) were used to investigate the structure of the oxide layer, composition of physical phase, wear surface morphology and elemental composition. The results show that the average coefficient of friction of 10Mn5 steel is 12.7% lower than that of 22MnB5 steel. The cross-section of both steel consists of an oxide layer, an alloying element-rich layer and the matrix. The oxide layer of 10Mn5 steel is mainly composed of Fe₃O₄, approximately 63.7%, while that of 22MnB5 is mainly composed of Fe₂O₃, approximately 66.9%. The complete and less flaking scale of 10Mn5 steel provides good wear protection, and the mechanism is abrasive with slight adhesive wear. Meanwhile, oxide particles and fragments are embedded in the 22MnB5 surface thus increasing the wear, and the mechanism evolves into severe abrasive and adhesive wear. The difference in the mechanism between the two steels is mainly caused by different austenitizing temperatures, which for 10Mn5 is lower than 22MnB5, about 100 °C. This makes the thermal stress of 10Mn5 from the temperature difference between the furnace and the environment not enough to break the scale and decrease abrasion. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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25 pages, 9084 KiB

Open AccessArticle

Time-Varying Wear Calculation Method for Fractal Rough Surfaces of Friction Pairs

by Qiang Hao, Jian Yin, Yu Liu, Lu Jin, Shengfang Zhang and Zhihua Sha

Coatings 2023, 13(2), 270; https://doi.org/10.3390/coatings13020270 - 25 Jan 2023

Cited by 1 | Viewed by 1240

Abstract

For the wear problem of the real rough surface during sliding friction, based on fractal theory and Hertz contact theory, a 3-D fractal rough surface with random characteristics is constructed, and the relationship between the wear deformation depth of the rough peak and [...] Read more.

For the wear problem of the real rough surface during sliding friction, based on fractal theory and Hertz contact theory, a 3-D fractal rough surface with random characteristics is constructed, and the relationship between the wear deformation depth of the rough peak and its real contact area during the wear process is derived. Furthermore, considering the peak wear and pit scratch phenomena of rough surfaces in different contact states, the time-varying wear calculation model of the worn surface and the compensation wear calculation model of the unworn surface are established, respectively, and the relationship between the instantaneous wear amount and the dynamic change in the rough surface topography is comprehensively characterized. Combined with image digitization technology, the 3-D rough surface is converted into a 2-D discrete plane with 3-D information. According to the dynamic real-time update of the graph data, the iterative calculation of the wear cycle is completed, the time-varying wear calculation method for fractal rough surfaces of friction pairs is proposed, and the dynamic change in the wear amount and surface topography of the rough surface is simulated. The simulation results are experimentally verified and the influence of friction parameters on the surface topography is analyzed. The results show that after the wear simulation, the profile height of the rough surface is reduced, and the average wear depth is 0.02 mm. Increases in rotational speeds and external loads can exacerbate surface wear, surface topography tends to be flattened, and surface carrying capacity increases. This provides theoretical guidance for the development and manufacture of friction pairs. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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15 pages, 10906 KiB

Open AccessFeature PaperArticle

The Mode Deformation Effect on Surface Nanocrystalline Structure Formation and Wear Resistance of Steel 41Cr4

by Volodymyr Kyryliv, Olha Maksymiv, Volodymyr Gurey, Ihor Hurey, Yaroslav Kyryliv and Olha Zvirko

Coatings 2023, 13(2), 249; https://doi.org/10.3390/coatings13020249 - 21 Jan 2023

Cited by 3 | Viewed by 1295

Abstract

A surface nanocrystalline steel layer in the low alloy steel 41Cr4 was fabricated by using mechanical-pulse treatment (MPT) with different deformation modes. The structure parameters, the physical and mechanical properties, the wear resistance, and the surface topography parameters of the treated steel depending [...] Read more.

A surface nanocrystalline steel layer in the low alloy steel 41Cr4 was fabricated by using mechanical-pulse treatment (MPT) with different deformation modes. The structure parameters, the physical and mechanical properties, the wear resistance, and the surface topography parameters of the treated steel depending on the deformation mode were investigated. A tool with a smooth working surface was used for inducing unidirectional deformation in the top surface layer (shear), and a tool with the oppositely directed grooves was used for generating multidirectional deformation. The surface layer with a nanocrystalline structure formed by MPT using both of the tools was characterised by enhanced mechanical properties and wear resistance compared with those of the untreated or heat-treated steels. Inducing multidirectional deformation during the MPT resulted in a decrease in the grain size and an increase in the depth and microhardness of the surface layer due to it facilitating the generation of dislocations compared to those formed under unidirectional deformation. The results also demonstrated that favourable surface topography parameters providing the highest wear resistance of the steel were obtained at MPT using multidirectional deformation. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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15 pages, 6335 KiB

Open AccessArticle

Comparison of Novel Low-Carbon Martensitic Steel to Maraging Steel in Low-Cycle Fatigue Behavior

by Bo Lv, Shule Xia, Fucheng Zhang, Guang Yang and Xiaoyan Long

Coatings 2022, 12(6), 818; https://doi.org/10.3390/coatings12060818 - 10 Jun 2022

Cited by 3 | Viewed by 1290

Abstract

The study systematically compares the low-cycle fatigue (LCF) behaviors of novel martensitic steel (22MnSi2CrMoNi) and maraging steel (00Ni18Co9Mo4Ti). Results show that the two types of tested steel have a similar cyclic deformation behavior. The cyclic softening resistance of 22MnSi2CrMoNi steel is slightly inferior [...] Read more.

The study systematically compares the low-cycle fatigue (LCF) behaviors of novel martensitic steel (22MnSi2CrMoNi) and maraging steel (00Ni18Co9Mo4Ti). Results show that the two types of tested steel have a similar cyclic deformation behavior. The cyclic softening resistance of 22MnSi2CrMoNi steel is slightly inferior to that of 00Ni18Co9Mo4Ti steel at a low total strain amplitude. However, the gap gradually disappears with the increase of the total strain amplitude. At the same plastic strain amplitude, the LCF lifetime of 22MnSi2CrMoNi steel is higher than that of 00Ni18Co9Mo4Ti steel. The retained austenite film between martensite lath and the existence of precipitated phase in matrix can effectively improve the fatigue lifetime of the two types of tested steel. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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15 pages, 5346 KiB

Open AccessArticle

Tribological Properties of the 40Cr/GCr15 Tribo-Pair under Unidirectional Rotary and Reciprocating Dry Sliding

by Jialiang Cao, Huan Teng, Wurong Wang, Xicheng Wei and Hongshan Zhao

Coatings 2022, 12(5), 557; https://doi.org/10.3390/coatings12050557 - 20 Apr 2022

Cited by 3 | Viewed by 2014

Abstract

The unidirectional rotary and reciprocating sliding experiments of the 40Cr pin/GCr15 disc tribo-pair were carried out on the MFT-5000 Rtec friction and wear tester under the same test conditions with a sliding speed of 0.2 m/s and a load of 150 N. Compared [...] Read more.

The unidirectional rotary and reciprocating sliding experiments of the 40Cr pin/GCr15 disc tribo-pair were carried out on the MFT-5000 Rtec friction and wear tester under the same test conditions with a sliding speed of 0.2 m/s and a load of 150 N. Compared with reciprocating sliding, the tribo-pair in rotary sliding exhibits a stabler friction coefficient and better wear resistance. By analyzing the wear surface morphologies of the two pins, the main wear mechanism was found to be adhesive wear. For the tribo-layer of pin under reciprocating sliding, the surface microstructure plastically converges and forms a ridge from both sides to the middle, while a vortex structure is generated in the tribo-layer of pin under rotating sliding. The metamorphic structure and mircohardness of tribo-layer caused by the sliding forms are the key factors affecting the tribological properties. Full article

(This article belongs to the Special Issue Microstructure, Fatigue and Wear Properties of Steels)

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