scholarly journals Enhanced Axial Tension-tension Fatigue Resistance of a 51CrV4 Spring Steel by Cryogenic Treatment

2020 ◽  
Vol 72 (4) ◽  
pp. 138-151
Author(s):  
Chen Zhi ◽  
Gao Yuan ◽  
Yan Xian-Guo ◽  
Guo Hong ◽  
Huang Yao ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Cryogenic Treatment ◽  
Spring Steel ◽  
Thin Strip ◽  
Leaf Spring ◽  
Axial Tension ◽  
Axial Tensile ◽  
Tensile Fatigue ◽  
Conventional Heat Treatment ◽  
Dump Trucks

51CrV4 spring steel is widely used in heavy duty dump trucks ascribing to its superior mechanical properties. The fatigue life and strength of dump trucks are the main performance indicators that must be considered in the manufacturing process. Cryogenic treatment (CT) can improve the main performance of materials which has been proved by recently research. The effect of cryogenic treatment CT on the axial tensile fatigue strength of 51CrV4 spring steel was studied in this paper. The results showed that the axial tension-tension fatigue life of 51CrV4 spring steel after CT was significantly higher than conventional heat treatment (CHT) samples. The microstructure of 51CrV4 leaf spring material is mainly acicular bainite and thin strip martensite after CT. Compared with CHT, CT makes the microstructure of the material more compact. The introduction of cryogenic treatment (CT) before tempering makes the Ca element in the material aggregate, and the micro amount of Ca has the function of deoxidizing and desulphurizing and improving the morphology of sulfide, thus enhancing the fatigue life of the material.

scholarly journals Design and Fatigue Analysis of Shot Peened Leaf Spring

2019 ◽  
Vol 9 (1) ◽  
pp. 1120-1126
Keyword(s):  
Fatigue Life ◽  
Shot Peening ◽  
High Strength ◽  
Load Level ◽  
Spring Steel ◽  
Leaf Spring ◽  
Leaf Springs ◽  
Point Test ◽  
Life Improvement ◽  
The Impact

The paper handles the fatigue and failing analysis of serial shot-peened leaf springs of cumbersome vehicles emphasizing on the impact of shot peening on fatigue life, coping with automotive leaf springs, the shot peening method turns into an important step in production.In the situation of leaf spring suspensions, however, asystematic research of the effect of shot peening about fatigue life isstill required. Experimental stress-life curves are determined with the aid of the usage of investigating clean specimen subjected to shot peening. those test consequences are as compared to corresponding ones identified from cyclic three-point test on shot peened serial leaf springs in order to show the influence of applied heat treatment and shot peening approach on fatigue existence of high-strength used to get leaf spring manufacturing, reliant on the load level. Analyses are performed to explain the effects resulting from shot peening practice on the surface features of the high-strength spring steel under examination. The evaluation of fatigue results shows that almost no life improvement due to production highlighting the importance for mutual variation in parameters of shot peening and thermal treatment so that there is sufficient progress in life

Optimized Modelling and Fabrication of a Parabolic Leaf Spring With Finite Element Analysis

2017 ◽  
Author(s):  
Md Tahsin Ishtiaque ◽  
Sung-Hwan Joo
Keyword(s):  
Fatigue Life ◽  
Structural Steel ◽  
Base Material ◽  
Spring Steel ◽  
Suspension System ◽  
Leaf Spring ◽  
Optimized Design ◽  
Profile Design ◽  
Flat Profile ◽  
Parabolic Leaf Spring

A leaf spring is a simple form of spring commonly used for suspension system of vehicles which is originally called laminated or carriage spring. They perform isolation task in transferring vibration due to road irregularities to driver’s body. To improve the suspension system, many modifications have taken place overtime but recent innovations imply parabolic leaf spring and application of composite materials for these springs. The conventional flat profile of the leaf spring has been transformed into parabolic leaf spring which facilitates lighter, cheaper, better fatigue life and isolating more noise. This project basically includes designing a leaf spring with a conventional flat profile design following the standard dimension (SAE Manual) with acceptable tolerance and regard it as the base model for the project. To obtain the deformation, stress and fatigue life of the base model; a Computer Aided Simulation has been carried out in ANSYS Workbench considering the Structural Steel as the base material. Afterwards, the conventional flat profile design has been changed to parabolic shape consisting 1 Master leaf and 3 graduated leaves. In this case, initially the structural steel has been selected as the base material and later on SAE 5160 steel has been implemented to carry out the simulation. As only spring steel is the material widely used for parabolic leaf spring and many research has been carried out with spring steel, therefore different materials with combination of different spring design has been carried out in this project to get a better life cycle compared to the widely used one. After first modification, number of leaves has been increased to 5 but analysis has been carried out with the same two materials considered for initial simulation. Due to time constraint, the final optimized design has been selected among the analysis finished with the combination of leaves and materials which incorporate the better fatigue life, reduced deformation, reduced weight of the spring and increased factor of safety and later on following the final design (analyzed from CAE results) the parabolic leaf spring has been built with the assistance of a spring shop.

Investigation into the Effects of Shot Peening on the Fretting Fatigue Behaviour of 65Si7 Spring Steel Leaf Springs

2005 ◽  
Vol 219 (3) ◽  
pp. 139-147 ◽  
Author(s):  
M L Aggarwal ◽  
R A Khan ◽  
V P Agrawal
Keyword(s):  
Fatigue Life ◽  
Shot Peening ◽  
Fatigue Behaviour ◽  
Fretting Fatigue ◽  
Surface Characteristic ◽  
Spring Steel ◽  
Leaf Spring ◽  
Damping Factor ◽  
Leaf Springs ◽  
Leaf Surfaces

Leaf springs are subjected to varying stresses and vibrations due to road conditions. The influence of high contact pressures and temperatures follow fretting fatigue between two mating leaf surfaces. The work presented in this paper relates to improvement in fatigue and fretting fatigue performance of leaf springs using shot peening and coatings. The fatigue life of 65Si7 spring steel leaf springs has been determined experimentally at various shot peening conditions and optimum shot peening intensity is found. Full-scale leaf spring laboratory testing and specimen testing were carried out to show the extent of improvement in fatigue life as a result of shot peening. Structural damping is found to be an important surface characteristic of shot peened surfaces for reducing fretting fatigue. The effects of shot peening conditions and damping factor for minimizing fretting fatigue failures are discussed.

scholarly journals Effects of Pre-Tensile Deformation on the Fatigue Fracture Behavior of Annealed 7005 Aluminum Alloy Plate

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 623
Author(s):  
Ni Tian ◽  
Zhen Feng ◽  
Xu Shi ◽  
Wenze Wang ◽  
Kun Liu ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Fatigue Fracture ◽  
Tensile Deformation ◽  
Thin Strip ◽  
Second Phase ◽  
Alloy Matrix ◽  
Alloy Plate ◽  
Dislocation Distribution ◽  
Aluminum Alloy Plate

In the present study, the fatigue life and fatigue fracture characteristics of annealed 7005 aluminum alloy plates subjected to different pre-tensile deformations were investigated. The results obtained upon increasing the pre-tensile deformation of the alloy plate to 20% revealed that the second-phase particles did not show any obvious changes, and that the thickness of the thin strip grain slightly decreased. The dislocation distribution in the alloy matrix varied significantly among the grains or within each grain as the dislocation density gradually increased with increasing pre-tensile deformation. Moreover, the fatigue performance of the annealed 7005 aluminum alloy plate was significantly improved by the pre-tensile deformation, and the alloy plate subjected to 20% pre-tensile deformation exhibited an optimal fatigue life of ~1.06 × 106 cycles, which was 5.7 times and 5.3 times that of the undeformed and 3% pre-stretched alloy plates, respectively. Two fatigue life plateaus were observed in the pre-tensile deformation ranges of 3–5% and 8–12%, which corresponded to heterogeneous dislocation distribution among various grains and within each grain, respectively. Moreover, two large leaps in the plot of the fatigue-life–pre-tensile-deformation curve were observed, corresponding to the pre-tensile deformation ranges of 5–8% and 16–20%, respectively.

Effects of Water Jet Peening and Hardening Treatment on Fatigue Properties of SCr420

2009 ◽  
Author(s):  
Akira Shimamoto ◽  
Ryo Kubota ◽  
Sung-mo Yang ◽  
Dae-kue Choi ◽  
Weiping Jia
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Water Jet ◽  
Fatigue Properties ◽  
In Situ Observation ◽  
Axial Tensile ◽  
High Pressure Water Jet

An experimental study of high pressure water jet peening treatment on chromium steal SCr420 H3V2L2 is conducted to study the effects of cavitation impacts of high-speed water on fatigue crack initiation and propagation of notched specimens. There are six different kinds of specimens. First three kinds are treated with; only annealing, only water quenching, and only oil quenching. Other three kinds are treated with above heat treatment and water jet peening, respectively. An axial tensile fatigue tests’ condition is 260MPa maximum stress amplitude, 0 stress ratio and 10Hz frequency, while in-situ observation by SEM is employed. Although fatigue life of the specimens with annealing and water jet peening is shorter than that of only annealing, fatigue life of water and oil quenching with water jet peening specimens is obviously longer than those without water jet peening treatment. Water jet peening has increased residual stress inside the specimens on the latter case and raised their fatigue strength. In-situ observation on the crack tips approves above analysis.

Accounting for Inclusions and Voids Allows the Prediction of Tensile Fatigue Life of Bone Cement

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Oliver J. Coultrup ◽  
Martin Browne ◽  
Christopher Hunt ◽  
Mark Taylor
Keyword(s):  
Fatigue Life ◽  
Bone Cement ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Acoustic Emissions ◽  
Gauge Length ◽  
Uniaxial Tensile ◽  
Micro Computed Tomography ◽  
Dog Bone ◽  
Tensile Fatigue

Previous attempts by researchers to predict the fatigue behavior of bone cement have been capable of predicting the location of final failure in complex geometries but incapable of predicting cement fatigue life to the right order of magnitude of loading cycles. This has been attributed to a failure to model the internal defects present in bone cement and their associated stress singularities. In this study, dog-bone-shaped specimens of bone cement were micro-computed-tomography (μCT) scanned to generate computational finite element (FE) models before uniaxial tensile fatigue testing. Acoustic emission (AE) monitoring was used to locate damage events in real time during tensile fatigue tests and to facilitate a comparison with the damage predicted in FE simulations of the same tests. By tracking both acoustic emissions and predicted damage back to μCT scans, barium sulfate (BaSO4) agglomerates were found not to be significant in determining fatigue life (p=0.0604) of specimens. Both the experimental and numerical studies showed that diffuse damage occurred throughout the gauge length. A good linear correlation (R2=0.70, p=0.0252) was found between the experimental and the predicted tensile fatigue life. Although the FE models were not always able to predict the correct failure location, damage was predicted in simulations at areas identified as experiencing damage using AE monitoring.

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