Effect of Plating Thickness on Fatigue Strength of Galvanized Steel

2020 ◽  
Vol 841 ◽  
pp. 3-8
Author(s):  
Kayo Hasegawa ◽  
Tatsuo Hayashi ◽  
Motoaki Morita ◽  
Shinichi Motoda
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Main Crack ◽  
Immersion Time ◽  
Room Temperature ◽  
Columnar Structure ◽  
Galvanized Steel ◽  
Fatigue Properties ◽  
Plating Layer

Effect of the plating thicknesses on tensile and fatigue properties of hot-dip galvanized steel at room temperature was evaluated. The galvanized steel with thickness of 100 μm and 200 μm were prepared. Both microstructures of η-phase and δ1-phase were similar with each other. In the comparison with the galvanized steel with thickness of 100 μm, the microstructure of ζ-phase for the galvanized steel with thickness of 200 μm was blunt columnar structure due to long immersion time. Tensile and fatigue strengths for a galvanized steel are sensitive to the microstructure of the galvanized layer. The tensile strength and the strength of fatigue limit for the galvanized steel with thickness of 200 μm were smaller than that of 100 μm. In the galvanized steel with thickness of 200 μm, the peeling at plating layer easily occurred. The exfoliated sites have the potential to become subcracks. As the result, the main crack may propagate at early cycles.

High Cycle Fatigue Properties of Modified 9Cr-1Mo Steel at Elevated Temperatures

2012 ◽  
Author(s):  
Yoshiaki Matsumori ◽  
Jumpei Nemoto ◽  
Yuji Ichikawa ◽  
Isamu Nonaka ◽  
Hideo Miura
Keyword(s):  
Fatigue Strength ◽  
Fatigue Limit ◽  
Room Temperature ◽  
Structural Reliability ◽  
High Cycle Fatigue ◽  
Elevated Temperatures ◽  
Fatigue Behavior ◽  
Cyclic Softening ◽  
Fatigue Properties ◽  
Cycle Fatigue

Since high-cycle fatigue loads is applied to the pipes in various energy and chemical plants due to the vibration and frequent temperature change of fluid in the pipes, the high-cycle fatigue behavior of the alloys used for pipes should be understood quantitatively in the structural reliability design of the pipes. The purpose of this study, therefore, is to clarify the high-cycle fatigue strength and fracture mechanism of the modified 9Cr-1Mo steel at temperatures higher than 400°C. This material is one of the effective candidates for the pipes in fast breeder demonstration reactor systems. A rotating bending fatigue test was applied to samples at 50 Hz in air. The stress waveform was sinusoidal and the stress ratio was fixed at −1. The fatigue limit was observed at room temperature and it was about 420 MPa. This value was lower than the 0.2% proof stress of this alloy by about 60 MPa. This decrease can be attributed to the cyclic softening of this material. The limited cycles at knee point was about 8×105 cycles. All fracture was initiated from a single surface crack and no inclusion-induced fracture was observed in the fracture surface by SEM. Thus, the high-cycle fatigue design based on the fatigue limit may be applicable to the modified 9Cr-1Mo steel at room temperature. The fatigue limit of about 350 MPa was also observed at 400°C, and it appeared at about 107 cycles, while it appeared at around 106 cycles at room temperature. Thus, it was confirmed that the fatigue strength of this alloy decrease with temperature. However, the fatigue limit didn’t appear at 550°C up to 108 cycles. The fatigue limit may disappear in this alloy at 550°C. It is very important, therefore, to evaluate the ultra-high cycle fatigue strength of this alloy at temperatures higher than 400°C.

scholarly journals Fatigue Properties of Hot-Dip Galvanized AISI 1020 Normalized Steel in Tension–Compression and Tension–Tension Loading

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7480
Author(s):  
Shatumbu Thomas Alweendo ◽  
Motoaki Morita ◽  
Kayo Hasegawa ◽  
Shinichi Motoda
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Heat Effect ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Steel Substrate ◽  
Galvanized Steel ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Tension Loading

Since hot-dip galvanizing causes a heat effect on cold-worked steel substrate and produces a coating layer comprised of distinct phases with varying mechanical properties, the fatigue mechanism of hot-dip galvanized steel is very complex and hard to clarify. In this study, AISI 1020 steel that has been normalized to minimize susceptibility to the heat effect was used to clarify the effect of the galvanizing layer on the tensile and fatigue properties. The galvanizing layer causes a reduction in the yield point, tensile strength, and fatigue strength. The reduction in the fatigue strength was more significant in the high cycle fatigue at R = 0.5 and 0.01 and in the low cycle fatigue at R = 0.5. The galvanizing layer seems to have very little effect on the fatigue strength at R = −1.0 in the low and high cycle fatigue. Since the fatigue strengths at R = 0.01 and −1.0 in the low cycle fatigue were strongly related to the tensile strength of the substrate, the cracking of galvanized steel was different than that of non-galvanized steel. The fatigue strength of galvanized steel at R = 0.5 dropped remarkably in the low cycle fatigue in comparison to the non-galvanized steel, and many cracks clearly occurred in the galvanizing layer. The galvanizing layer reduced the fatigue strength only under tension–tension loading. We believe that the findings in this study will be useful in the fatigue design of hot-dip galvanized steel.

Effect of Thermal Exposure on Tensile and Fatigue Properties of Clay Reinforced Nylon Nanocomposites

2015 ◽  
Vol 833 ◽  
pp. 52-55
Author(s):  
Yukiko Nakahara ◽  
Yusuke Kodama ◽  
Shi Jie Zhu ◽  
Arimitsu Usuki ◽  
Makoto Kato
Keyword(s):  
Tensile Strength ◽  
Room Temperature ◽  
Thermal Exposure ◽  
Tensile Tests ◽  
Nylon 6 ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Oxidation Treatment ◽  
Exposure Temperature ◽  
Matrix Nanocomposite

In this paper, both nylon 6 and 2 wt% clay reinforced nylon 6 matrix nanocomposite were used for thermal exposure tests at temperatures of 80 oC and 120 oC and 150 oC, respectively. Then, the tensile tests and fatigue tests of the exposed specimens were conducted at room temperature. It was shown that the tensile strength in both nylon 6 and NCH-2 decreased with an increase in thermal exposure temperature. The brittle fracture occurred in the specimens exposed at 120 oC and 150 oC. After pre-oxidation treatment at 80 °C for 100 hours, the fatigue strength decreased 14% in nylon 6, and 8% in NCH-2. From this result, it was understood that the addition of clay in nylon 6 could suppress the decrease of fatigue strengths.

Effect of Plastic Working on Fatigue Properties of Ti-6Al-4V Alloy with Notch

2005 ◽  
Vol 297-300 ◽  
pp. 2513-2518
Author(s):  
Nobusuke Hattori ◽  
Shinichi Nishida ◽  
Masahiro Hara ◽  
Sun Young Son
Keyword(s):  
Fatigue Strength ◽  
Fatigue Limit ◽  
Work Hardening ◽  
Fatigue Cracks ◽  
Fatigue Properties ◽  
Plastic Working

This study is focused to the effects of plastic working on the fatigue strength of Ti-6Al-4V alloy with notch. In general, the fatigue strength of plastic worked specimen is higher than that of non-worked one. However, the potential of hardening ability of Ti-6Al-4V alloy is very limited. Accordingly, the effect of work hardening on fatigue strength about this material is very small. In addition, the surface of the worked part becomes rougher with increasing plastic deformed value and the fatigue cracks initiate at this part. Consequently, the fatigue limit of the plastic worked specimen is lower than that of the non-plastic-worked one.

FATIGUE PROPERTIES OF AUTOMOBILE HIGH-STRENGTH BOLTS

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5539-5544 ◽  
Author(s):  
CONGLING ZHOU ◽  
SHIN-ICHI NISHIDA ◽  
NOBUSUKE HATTORI
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Stress Level ◽  
High Strength ◽  
Fatigue Properties ◽  
Screw Thread ◽  
Mean Stress ◽  
Stress Levels ◽  
The Mean

This study is focused on the fatigue properties of automobile high-strength bolts, including the effect of mean stress level, pre-processing schedule and the residual stresses. And the mean stress levels are 0.3, 0.5 and 0.7 times to the tensile strength (σ B ) of the material respectively. The main results obtained are as follows: 1) the fatigue strength increases under the mean stress loading, but the differences between the loading levels are not so evident; 2) most of the cases in this study are broken from the bottom of the screw thread, and the crack initiated from the impurities.

Study on Rotating Bending Fatigue Property of Ti65 Titanium Alloy

2016 ◽  
Vol 849 ◽  
pp. 347-352
Author(s):  
Xu Wang ◽  
Si Qing Li ◽  
Jing Nan Liu
Keyword(s):  
Titanium Alloy ◽  
Fatigue Strength ◽  
Room Temperature ◽  
Fatigue Property ◽  
Fatigue Properties ◽  
Bending Fatigue ◽  
Notched Specimens ◽  
Different Temperatures ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

The rotating bending fatigue properties of Ti65 titanium alloy blisk forging was studied in the present investigation. The smooth and notched specimens were prepared to test the fatigue properties at room temperature and 650°C. Meanwhile, the influences on rotating bending fatigue of temperature and type were analyzed. Furthermore, the fractural morphology was observed through scanning electron microscopy. The results showed that the medium fatigue strength of Ti65 titanium alloy decreased at 650°C compared with that at room temperature, and the fatigue strength of notched specimens indicated the same significant declination at different temperatures compared with smooth specimens. At room temperature the medium fatigue strength of smooth and notched are 473MPa and 173MPa, respectively, and the fatigue notch sensitive coefficient was 0.87. At 650°C the medium fatigue strength of smooth and notched specimens are 427MPa and 168MPa, where the fatigue notch sensitive coefficient was 0.78.

scholarly journals The Behavior of Graphite Under Alternating Stress

1951 ◽  
Vol 18 (4) ◽  
pp. 345-348
Author(s):  
Leon Green
Keyword(s):  
Tensile Strength ◽  
Room Temperature ◽  
Endurance Limit ◽  
Elevated Temperatures ◽  
Fatigue Properties ◽  
Polycrystalline Graphite ◽  
Short Time

Abstract The fatigue properties of grade AUF extruded polycrystalline graphite were investigated at ambient and elevated temperatures. Specimens cut parallel to the axis of extrusion were stressed in reversed bending at room temperature and at 3550 F. The endurance limit of this graphite was found to increase from 2500 psi at room temperature to about 4400 psi at 3550 F. The increase in endurance limit is correlative with the increase in short-time tensile strength with temperature observed in earlier studies of graphite.

Effects of Torsional Plastic Deformation on Fatigue Strength in Copper and Aluminum

2010 ◽  
Vol 452-453 ◽  
pp. 597-600
Author(s):  
Chobin Makabe ◽  
K. Kuniyoshi ◽  
Masaki Fujikawa ◽  
Ryouji Kondou ◽  
D. Shinohara
Keyword(s):  
Tensile Strength ◽  
Surface Layer ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Material Strength ◽  
Face Centered Cubic ◽  
Torsional Deformation ◽  
Cross Sectional ◽  
Rotating Bending Fatigue ◽  
Center Section

If the crystal grain size of a metal is made smaller, its strength is higher. So, many methods of grain refinement have been proposed. In this study, from the viewpoint of basic plastic working, the variations of static ultimate tensile strength and fatigue strength after the application of plastic torsional deformation on face centered cubic crystal metals, that are, aluminum and copper, were investigated. Tensile test, Vickers harness test and Rotating bending fatigue test were performed. The hardness of the materials varied from surface layer to center section in cross sectional area. In the case of aluminum, the tensile strength and fatigue limit were improved after application of torsional deformation. However, in the case of copper, the fatigue limit was not improved. This is strongly related to hardness distribution around the surface layer of the specimen. Also, it was found that the crack growth mode was changed by applying the pre-strain. From these results, one of an idea for improvement of material strength will be considered.

Fatigue and Fretting Fatigue Behavior of Metallic Biomaterials

2010 ◽  
Vol 638-642 ◽  
pp. 618-623
Author(s):  
Norio Maruyama
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Fatigue Behavior ◽  
Fretting Fatigue ◽  
Test Method ◽  
Fatigue Properties ◽  
Metallic Biomaterials ◽  
The Relationship

A fretting fatigue test method in a simulated body fluid is shown to evaluate fatigue properties of metallic materials which are used in the orthopaedics field. Next, fatigue/fretting fatigue behavior in a simulated body fluid is given for 316L stainless steel, Ti-6% Al-4% V alloy, pure Ti for industrial use and Co-Cr-Mo alloy. Finally, we discuss the relationship between the tensile strength and the fatigue strength/fretting fatigue strength of metallic biomaterials at 107 cycles in air and in a simulated body fluid. For all of the biomaterials tested, the fatigue strength at 107 cycles is similar in air and in a simulated body fluid. The fatigue strength is closely correlated to the tensile strength: The fatigue strength increases with increasing tensile strength. However, a correlation is not observed between the fretting fatigue strength at 107 cycles and the fatigue strength or the tensile strength.

Effects of anisotropic pore structure and fiber texture on fatigue properties of lotus-type porous magnesium

2007 ◽  
Vol 22 (11) ◽  
pp. 3120-3129 ◽  
Author(s):  
H. Seki ◽  
M. Tane ◽  
H. Nakajima
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Ultimate Tensile Strength ◽  
Fracture Surface ◽  
Pore Structure ◽  
Longitudinal Axis ◽  
Fiber Texture ◽  
Fatigue Properties ◽  
Direction Parallel ◽  
Porous Magnesium

We studied the effects of anisotropic pores and fiber texture on the fatigue strength and fracture surface of lotus-type porous magnesium fabricated through unidirectional solidification in pressurized hydrogen and argon atmospheres. The fatigue strength in the direction parallel to the longitudinal axis of pores is higher than that in the perpendicular direction. Not only anisotropic pores but also fiber texture grown along the pore direction contributes to the anisotropy in the fatigue strength. The fatigue strength at finite life of lotus magnesium is closely related to the ultimate tensile strength; the fatigue strength is proportional to the ultimate tensile strength for both loadings parallel and perpendicular to the pore direction. The fracture surface of lotus magnesium is not flat, which originates from porous structure. For parallel loading, fiber texture in lotus magnesium also contributes to the irregular surface, i.e., a combination of texture and pore structure affects fracture surfaces.

Sign in / Sign up

Export Citation Format

Share Document