Factors Influencing the Fatigue Behavior of Ferrous Laminates

1987 ◽  
Vol 109 (3) ◽  
pp. 244-251 ◽  
Author(s):  
J. Wittenauer ◽  
O. D. Sherby
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Fatigue Behavior ◽  
Layered Material ◽  
Factors Influencing ◽  
Ultrahigh Carbon Steel ◽  
Processing History ◽  
Crack Blunting ◽  
Similar Processing

Laminates based on ultrahigh carbon steel were prepared and found to exhibit enhanced fatigue life as compared to a monolithic reference material. This result was achieved through the insertion of weak interlaminar regions of copper into the layered material during preparation of the laminates. The presence of these regions allowed for the operation of a delamination mechanism in advance of the propagating fatigue crack. The result was interlaminar separation and associated crack blunting. Stress-life curves show that an increase in life by as much as a factor of four is achieved for these materials when compared to monolithic specimens of similar processing history.

scholarly journals Rapid fatigue life prediction for spot-welded joint of SUS301 L-DLT stainless steel and Q235B carbon steel based on energy dissipation

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881101 ◽  
Author(s):  
Yaliang Liu ◽  
Yibo Sun ◽  
Yang Sun ◽  
Hongji Xu ◽  
Xinhua Yang
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Energy Dissipation ◽  
Life Prediction ◽  
Welded Joint ◽  
Fatigue Behavior ◽  
Dissimilar Materials ◽  
Fatigue Life Prediction ◽  
Spot Welded

Spot welding of dissimilar materials can utilize the respective advantage comprehensively, of which reliable prediction of fatigue life is the key issue in the structure design and service process. Taking into account almost all the complex factors that have effects on the fatigue behavior such as load level, thickness, welding nugget diameter, vibrational frequency, and material properties, this article proposed an energy dissipation-based method that is able to predict the fatigue life for spot-welded dissimilar materials rapidly. In order to obtain the temperature gradient, the temperature variations of four-group spot-welded joint of SUS301 L-DLT stainless steel and Q235 carbon steel during high-cycle fatigue tests were monitored by thermal infrared scanner. Specifically, temperature variation disciplines of specimen surface were divided into four stages: temperature increase, temperature decrease, continuous steady increase in temperature, and ultimate drop after the fracture. The material constant C that a spot-welded joint of dissimilar material needs to reach fracture is 0.05425°C·mm3. When the specimen was applied higher than the fatigue limit, the highest error between experimental values and predicted values is 18.90%, and others are lower than 10%. Therefore, a good agreement was achieved in fatigue life prediction between the new method and the validation test results.

Measurement on Scale-Induced Fatigue Behaviour for Railway Axle

2008 ◽  
Vol 44-46 ◽  
pp. 65-70 ◽  
Author(s):  
Yong Xiang Zhao ◽  
Bing Yang ◽  
Ming Fei Feng
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Fatigue Limit ◽  
Fatigue Behavior ◽  
Fatigue Behaviour ◽  
Railway Axle ◽  
Material Fatigue ◽  
Lz50 Steel ◽  
The Difference

Transferring of fatigue behavior is investigated from material to structure for Chinese railway LZ50 axle carbon steel. S-N data in mid-fatigue life range and fatigue limit data of smooth small specimens are applied for material fatigue behavior. Real axles and similar smooth bigger specimens were tested with respect to fatigue limits. The data of real axles reveal the difference between material and a special structure. And the data of similar specimens play a role of bridge to connect material and material structures. Probabilistic transferring relations are deduced by the data from material, to similar specimens, and then to structures at the fatigue limit phase. Structural probabilistic S-N curves are obtained by the material fatigue behavior to extend the transferring relations to entire fatigue life range. Determinations of the fatigue behavior of the groove of LZ50 steel axle indicate availability of the present investigation.

EFFECT OF CERAMIC COATING THICKNESS ON RESIDUAL STRESS AND FATIGUE CHARACTERISTIC OF 1Cr-1Mo-0.25V STEEL

2002 ◽  
Vol 16 (01n02) ◽  
pp. 181-188 ◽  
Author(s):  
CHANG-MIN SUH ◽  
BYUNG-WON HWANG ◽  
KYUNG-RYUL KIM
Keyword(s):  
Residual Stress ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Coating Thickness ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Turbine Rotor ◽  
Fatigue Tests ◽  
Rotor Steel

To evaluate the effect of coatings on the fatigue behaviors of turbine rotor steel, TiN and TiAlN films were deposited on the 1Cr-1Mo-0.25V steels by arc-ion plating (AIP) method with and wihtout screen ion filter. The coating thickness were varied with 2.5 μm, 3.5 μm, and 5.0 μm. A Cu-K α beam source was used as a characteristic X-ray and the crystal plane of (422) was selected to evaluate the residual stresses. In order to clear the relationship between fatigue behavior and residual stress of specimen coated with TiN and TiAlN films, the fatigue tests of specimens with and without coating were carried out at room temperatures respectively. It is shown that the fatigue life of the coated specimen was longer than that of uncoated specimen. The compressive residual stresses on the coatings were higher, and the fatigue crack initiated at an inclusion in the substrate near bond interface. It is known that compressive residual stress caused by hard coating would retard the fatigue crack initiation on the specimen surface, and then led to fatigue strength and fatigue life increasing.

Experimental Study on Evolution Process of Short Fatigue Crack in 2A12 Alloy under Complex Stress State

2016 ◽  
Vol 703 ◽  
pp. 202-206
Author(s):  
Shan Lin Liu ◽  
Lu Wang ◽  
Zheng Wang
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Phase Particle ◽  
Fatigue Behavior ◽  
Crack Coalescence ◽  
Experimental Result ◽  
Second Phase ◽  
Middle Stage ◽  
Short Fatigue Crack

The fatigue behavior of 2A12 Aluminum alloy was experimentally studied through different annular notched specimens under symmetrical triangle with the frequency of 0.5 Hz. The experimental result showed that the microstructure played an important role during the entire fatigue life of 2A12 Aluminum alloy. The short fatigue crack only initiated due largely to the second-phase particle such as the S phase (Al2CuMg), the θ phase (CuAl2) and especially the black impurity phases debonding from the basal body when the fatigue cycle was sufficient. The cracks propagated separately along the circumferential direction of the notch, crack coalescence and interaction of cracks were not common at early and middle stage of short crack’s fatigue life. Cracks tended to propagate along direction different from the original one after crack coalescence. Surface crack length at early and middle stage of short crack’s fatigue life were presented. These curves showed crack growth rate increased relatively as the reducing of notched radius or the increasing of nominal strain amplitude which implied that geometry and loading conditions were the factors of the crack propagation.

scholarly journals Effect of Water Environment on Fatigue Behavior in X80 High Strength Steel CO2 Arc Welding Welded Joint

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 136
Author(s):  
Xiaohui Zhao ◽  
Gen Liu ◽  
Desheng Xu ◽  
Chunhua Hu ◽  
Yu Liu
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Initiation ◽  
Welded Joints ◽  
Arc Welding ◽  
Pipeline Steel ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Water Environment ◽  
X80 Pipeline Steel

Fatigue life tests and fatigue crack growth rate (FCGR) tests in the air and water environment were conducted on X80 pipeline steel welded joints (welded by CO2 arc welding). Scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) were utilized to investigate the internal influential mechanisms of the water environment during fatigue crack initiation and propagation stages, respectively. Results show that a great many oxide particles induced by the water environment gradually formed the fatigue crack initiation site and decreased fatigue life of welded joints. Meanwhile, the preferred grain orientation of <001>//ND and CSL boundaries of Σ3, Σ11, Σ13c, Σ17b, Σ25a, and Σ25b are both prone to fatigue propagation when loading in the water environment. In addition, a coalescence of the stress intensity factor (SIF) range and water environment accelerated FCGR by motivating secondary slip systems of {112}<111> and {123}<111> in bcc crystalline structures.

scholarly journals The Effect of Microstructure and Axial Tension on Three-Point Bending Fatigue Behavior of TC4 in High Cycle and Very High Cycle Regimes

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 68 ◽  
Author(s):  
Xuechun Bao ◽  
Li Cheng ◽  
Junliang Ding ◽  
Xuan Chen ◽  
Kaiju Lu ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Initiation ◽  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Bending Fatigue ◽  
Three Point Bending ◽  
Axial Tension ◽  
Very High

The effects of microstructure and axial tension on the fatigue behavior of TC4 titanium alloy in high cycle (HCF) and very high cycle (VHCF) regimes are discussed in this paper. Ultrasonic three-point bending fatigue tests at 20 kHz were done on a fatigue life range among 105–109 cycles of the alloys with equiaxed, bimodal and Widmanstatten microstructures. Experimental results without axial tension show that three typical shapes of S-N curves clearly present themselves for the three different microstructures. Moreover, the crack initiation sites abruptly shifted from surface to subsurface of the specimen in the very high cycle fatigue regime for equiaxed and bimodal microstructures. But for the Widmanstatten microstructure, both surface and subsurface crack initiation appeared in the high cycle fatigue regime, and the multi-points crack initiation was found in the bimodal microstructure. The subsurface fatigue crack originated from the αp grains in equiaxed and bimodal microstructures. However, it originated from the coarse grain boundary α in the Widmanstatten microstructure. Additionally, the S-N curve shape, fatigue life and fatigue crack initiation mechanism with axial tension are similar to that without axial tension. However, the crack origin point shifts inward with axial tension.

Fatigue Behavior of Medium Carbon Steel by Symmetric Bending Ultrasonic Frequency Method

2011 ◽  
Vol 393-395 ◽  
pp. 102-105
Author(s):  
Wei Wei Tang ◽  
Hong Wang ◽  
Jin Gan Dai
Keyword(s):  
Fatigue Crack ◽  
Carbon Steel ◽  
Crack Initiation ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Medium Carbon Steel ◽  
Fatigue Properties ◽  
Ultrasonic Frequency ◽  
Frequency Method ◽  
Medium Carbon

The S-N curves of medium carbon steel(MCS) are determined by the ultrasonic symmetric bending fatigue system (20 KHz). The results show that two S-N curves of MCS display the characteristic of “continually decreasing type” up to 109 cycles and exhibit no traditional horizontal plateau beyond 106 cycles. When the fatigue cycles are over 109, fatigue failure do occurs. By comparison of the two curves of 2mm thick and 5mm thick MCS, the results show that in the high-cycle stage(107cycles), size effect has no significant impact on fatigue Properties. This can also be explained by the theory of crack initiation, in high cycle stage, fatigue crack initiation exists in the sample surface, and in ultra-high-cycle stage, fatigue crack initiation exists in internal initiation.

Fatigue Behavior Comparisons Between Ultrasonic and Servohydraulic Axial Testing Procedures

2016 ◽  
Author(s):  
Onome Scott-Emuakpor ◽  
Tommy George ◽  
Casey Holycross ◽  
Jeffrey Brown ◽  
Joseph Beck
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Gas Turbine ◽  
Fatigue Behavior ◽  
Turbine Engine ◽  
Testing Procedures ◽  
Cycling Rate ◽  
Ultrasonic Fatigue ◽  
Cycles To Failure

An investigation of cycling rate effects on fatigue life behavior is being conducted on Aluminum (Al) alloys. This effect, along with specimen diameter, highlights the major difference between ultrasonic and servohydraulic fatigue test procedures. Ultrasonic fatigue testing is conducted on a 3.2 mm diameter hourglass specimen operating at 26 kHz, and servohydraulic axial testing is conducted on an ASTM E 466-07 standard dogbone specimen with a 25.4 mm gage length and 4.45 mm diameter operating at 35 Hz. Previous works have shown that cycling rate increases of 100–1000 times can reduce the fatigue crack growth rates in the stress intensity region between threshold and critical by at least an order of magnitude for aluminum and steel. For high cycle fatigue (HCF), however, where the majority of cycles to failure are accumulated before crack initiation, not during propagation, the effects of cycling rate on total loading cycles to failure needs further understanding, which may lead to more accurate and/or less conservative HCF design of critical gas turbine engine components. Fatigue behavior of Al 6061-T6 was assessed between the failure range of 104–1010 cycles using ultrasonic and servohydraulic testing procedures. Though aluminum is not a widely used alloy in gas turbine engine applications, understanding frequency-based fatigue life discrepancies associated with the choice of empirical methods is of paramount importance to component design; Aluminum 6061-T6 is the most cost-effective way to gaining this understanding. Comparisons were made between the fatigue behavior results using cycling rate (also stated as strain-rate or frequency) comparisons for fatigue crack growth study. The comparisons show promising results correlating the fatigue behavior trends of servhydraulic and ultrasonic fatigue data.

The Effect of Small Defects on Fatigue Life of a Low Carbon Steel

2019 ◽  
Author(s):  
Natalia Gonçalves Torres ◽  
Vinícius Rodrigues ◽  
Edgar Mamiya
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Low Carbon
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