Numerical Analysis of the Influence of Graphite Nodule Size on the Pitting Resistance of Austepered Ductile Iron Gears

2015 ◽  
Vol 1120-1121 ◽  
pp. 763-772 ◽  
Author(s):  
Luiz Henrique Accorsi Gans ◽  
Wilson Luiz Guesser ◽  
Marco Antonio Luersen ◽  
Carlos Henrique da Silva
Keyword(s):  
Wear Resistance ◽  
Ductile Iron ◽  
Maximum Shear Stress ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Graphite Nodule ◽  
Element Analysis ◽  
Aisi 4140 Steel ◽  
Nodule Size ◽  
Aisi 4140

In this work, an experimental study of wear evaluation in combination with a finite element analysis (FEA) was carried out for austempered ductile iron (ADI) used in gears. Two different ADI materials were used to produce gears which were tested in a FZG back-to-back test rig. The experimental results were compared to those of carburized AISI 8620 steel and induction hardened AISI 4140 steel gears. The wear resistance for pitting and spalling on the gears surfaces were measured using image analysis. Comparing the two types of ADI, the one with smaller nodules showed a higher pitting resistance. In contact fatigue tests with severe load, the carburized AISI 8620 steel proved to be superior to ADI. However, ADI with smaller nodule size presented wear resistance similar to that of induction hardened AISI 4140 steel. The FEA was conducted using the commercial code ANSYS 11.0 and aimed to provide a better understanding of the microstructural effect on the stress state of subsurface regions. From the numerical results in ADIs, it was concluded that the nodule size affects the gears life independently of the mechanical properties of the matrix. The size and number of nodules affects both the nucleation and the propagation stages of cracks. ADIs with higher amount of nodules have a superior wear resistance by pitting. Also, compared to the Hertz contact theory (valid for isotropic materials), the presence of graphite nodules induced the maximum shear stress point moves toward the surface.

MODELING AND INVESTIGATION OF THE WEAR RESISTANCE OF SALT BATH NITRIDED AISI 4140 VIA ANN

2013 ◽  
Vol 20 (03n04) ◽  
pp. 1350033 ◽  
Author(s):  
ŞERAFETTIN EKINCI ◽  
AHMET AKDEMIR ◽  
HUMAR KAHRAMANLI
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Surface Characterization ◽  
Wear Behavior ◽  
Surface Hardness ◽  
Salt Bath ◽  
Back Propagation Algorithm ◽  
Aisi 4140 Steel ◽  
Aisi 4140 ◽  
Sliding Distance

Nitriding is usually used to improve the surface properties of steel materials. In this way, the wear resistance of steels is improved. We conducted a series of studies in order to investigate the microstructural, mechanical and tribological properties of salt bath nitrided AISI 4140 steel. The present study has two parts. For the first phase, the tribological behavior of the AISI 4140 steel which was nitrided in sulfinuz salt bath (SBN) was compared to the behavior of the same steel which was untreated. After surface characterization using metallography, microhardness and sliding wear tests were performed on a block-on-cylinder machine in which carbonized AISI 52100 steel discs were used as the counter face. For the examined AISI 4140 steel samples with and without surface treatment, the evolution of both the friction coefficient and of the wear behavior were determined under various loads, at different sliding velocities and a total sliding distance of 1000 m. The test results showed that wear resistance increased with the nitriding process, friction coefficient decreased due to the sulfur in salt bath and friction coefficient depended systematically on surface hardness. For the second part of this study, four artificial neural network (ANN) models were designed to predict the weight loss and friction coefficient of the nitrided and unnitrided AISI 4140 steel. Load, velocity and sliding distance were used as input. Back-propagation algorithm was chosen for training the ANN. Statistical measurements of R2, MAE and RMSE were employed to evaluate the success of the systems. The results showed that all the systems produced successful results.

Influence of Forging Process on Fatigue Properties of AISI 4140 Steel Axle Component

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Venkateswaran Perumal ◽  
Sivakumar Palanivelu ◽  
Siba Prasad Mookherjee ◽  
Ajit Kumar Jindal
Keyword(s):  
Fatigue Testing ◽  
Front Axle ◽  
Fatigue Properties ◽  
Element Analysis ◽  
Aisi 4140 Steel ◽  
Forging Process ◽  
Aisi 4140 ◽  
Static Tensile ◽  
Static Yield ◽  
Hot Die Forging

The present paper investigates the microstructure and mechanical properties’ aspects of AISI 4140 steel front axle beams developed by roll and hot-die forging processes. Microstructure of the processed beams exhibited tempered martensite, and nonmartensitic products, such as retained austenite and ferrite at the case and core, respectively. Fatigue testing results indicate that roll forged beams have demonstrated 37% higher fatigue lives (Weibull B50 life) compared to hot-die forged beams, despite similar quasi-static tensile properties. The improved fatigue performance of the roll forged beams over hot-die forged beams is attributed to the fine, close texture and rationalized material flow in the beams processed by the roll forging process. Finite element analysis and experimental strain measurements of subject component indicate that the stress levels due to fatigue loads are well below the static yield strength and endurance limit of AISI 4140 steel; however, the notches present in the form of flash or partition lines of the forged beams have initiated the fatigue failures of the beams.

Wear Resistance of DCL Coating Deposited on Pretreated AISI 4140 Steel

2000 ◽  
Vol 2 (7) ◽  
pp. 444-448 ◽  
Author(s):  
B. Podgornik ◽  
J. Vižintin ◽  
H. Ronkainen ◽  
K. Holmberg
Keyword(s):  
Wear Resistance ◽  
Aisi 4140 Steel ◽  
Aisi 4140

Continuous damage-based Voronoi finite element analysis of contact fatigue of a wind turbine gear

2019 ◽  
Vol 233 (10) ◽  
pp. 1483-1495
Author(s):  
Peitang Wei ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Haifeng He
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Mechanical Response ◽  
Fatigue Behavior ◽  
Maximum Shear Stress ◽  
Contact Fatigue ◽  
Damage Mechanism ◽  
Mechanical Transmission ◽  
Element Analysis ◽  
Gear Contact

Contact fatigue failures of gears, especially those used in heavy duty conditions such as wind turbine gears, become important issues in mechanical transmission industry. In the present work, a continuous damage mechanism and Voronoi-based finite element model is developed to investigate the contact fatigue of a wind turbine gear. Plane strain assumption is adopted to simplify the gear contact model. Voronoi tessellations are utilized to represent the microstructure topology of the gear material, and continuous damage mechanism is implemented to reflect the material degradation within critical substrate area. With the developed framework, the contact pressure distribution, intergranular mechanical response and the progressive fatigue damage at the grain boundaries during repeated gear meshing are evaluated and discussed in detail. The depths of the maximum shear stress reversal and the crack initiation agree well with previously reported findings. The influence of microstructure on the gear contact fatigue behavior is also investigated.

Contact and bending fatigue behaviour of austempered ductile iron gears

2017 ◽  
Vol 232 (6) ◽  
pp. 998-1008 ◽  
Author(s):  
Carlo Gorla ◽  
Edoardo Conrado ◽  
Francesco Rosa ◽  
Franco Concli
Keyword(s):  
Ductile Iron ◽  
Contact Fatigue ◽  
Research Programme ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Austempered Ductile Iron ◽  
Fatigue Properties ◽  
Bending Fatigue ◽  
Metallurgical Analysis ◽  
Single Tooth

In the present paper a research programme aimed at investigating both the bending and contact fatigue properties of an austempered ductile iron applied to gears is presented, in order to determine reliable values of the limits, which take into account the influence of the production process, to be applied in the design of gearboxes. The bending fatigue tests are performed according to the single tooth fatigue approach and the pitting tests are performed with a back-to-back rig. Metallurgical analysis is performed on the failed specimens, in order to understand the origin and the propagation of the failures and to appreciate the influence of the micro-structure on the performances obtained.

Experimental and numerical evaluation of the contact fatigue resistance of AlCrN, FexN and AlCrN/FexN coatings on AISI 4140 steel

2021 ◽  
pp. 127620
Author(s):  
A. Ballesteros-Arguello ◽  
F.O. Ramírez-Reyna ◽  
G.A. Rodríguez-Castro ◽  
A. Meneses-Amador ◽  
D. Fernández-Valdés ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Numerical Evaluation ◽  
Contact Fatigue ◽  
Aisi 4140 Steel ◽  
Aisi 4140 ◽  
Contact Fatigue Resistance

Research on Contact Fatigue Properties of Some Materials Used for Heavy Load Gear

2010 ◽  
Vol 139-141 ◽  
pp. 360-363
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Er Yu Shao
Keyword(s):  
Fatigue Life ◽  
Crack Propagation ◽  
Maximum Shear Stress ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Experimental Results ◽  
Fatigue Properties ◽  
Heavy Load ◽  
Contact Fatigue Life ◽  
Materials Used

The contact fatigue tests were carried out using three kind of steel(45, 42CrMo, 40CrNi2Mo) which were quenched and tempered to the same medium hardness(HRC37±1). The experimental equipment is JPM-1 type contact fatigue tester. During the experiment process, the contact stress is 1600MPa and the surface roughness is 0.4 um. The crack initiation and the crack propagation direction were observed by using SEM. The contact fatigue failure mechanism was also analyzed. The experimental results were analyzed by using Weibull distribution. The experimental results show that the contact fatigue crack was initiated in the roller surface. With increasing of the cycle, the initiated crack propagates into subsurface and becomes to pitting. The pitting becomes bigger and bigger and leads to failure finally. The maximum shear stress is the main driving force for the crack propagation. The contact fatigue life increases in sequence of 45, 42CrMo, 40CrNi2Mo. The contact fatigue life has the relationship with the shearing resistant stress Тk. About the same carbon content, the value of the shearing resistant stress Тk becomes greater with increasing the alloying elements. The best material used for making heavy duty gear is 40CrNi2Mo steel.

scholarly journals Fatigue Analysis of Threaded Components with Cd and Zn-Ni Anticorrosive Coatings

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1455
Author(s):  
Jefferson Rodrigo Marcelino dos Santos ◽  
Martin Ferreira Fernandes ◽  
Verônica Mara de Oliveira Velloso ◽  
Herman Jacobus Cornelis Voorwald
Keyword(s):  
Stress Concentration ◽  
Stress Ratio ◽  
Fatigue Behavior ◽  
Base Material ◽  
Experimental Tests ◽  
Fatigue Tests ◽  
Element Analysis ◽  
Aisi 4140 ◽  
Stress Concentration Effect ◽  
Zinc Nickel

The influence of the electrodeposition of cadmium and zinc-nickel and the stress concentration effect on the fatigue behavior of AISI 4140 steel threaded components were studied. Axial fatigue tests at room temperature with a stress ratio of R = 0.1 were performed using standard and threaded specimens with and without nut interface under base material, cadmium, and zinc-nickel-coated conditions. Finite element analysis (FEA) was used, considering both elastic and elastoplastic models, to quantify the stress distribution and strain for threaded specimens with and without a nut interface. The numeric results were correlated to the experimental fatigue data of threaded components with and without the nut interface, to allow the oil & gas companies to extrapolate the results for different thread dimensions, since the experimental tests are not feasible to be performed for all thread interfaces. Scanning electron microscopy (SEM) was used to analyze the fracture surfaces. The stress concentration factor had a greater influence on the fatigue performance of threaded components than the effect of the Cd and Zn-Ni coatings. The fatigue life of studs reduced by about 58% with the nut/stud interface, compared to threaded components without nuts. The elastoplastic FEA results showed that studs with a stud/nut interface had higher stress values than the threaded specimens without a nut interface. The FEA results showed that the cracks nucleated at the regions with higher strain, absorbed energy, and stress concentration. The substitution of Cd for a Zn-Ni coating was feasible regarding the fatigue strength for threaded and smooth components.

Plastic Effects on High Cycle Fatigue at the Edge of Contact of Turbine Blade Fixtures

2017 ◽  
Author(s):  
C. H. Richter ◽  
U. Krupp ◽  
M. Zeißig ◽  
G. Telljohann
Keyword(s):  
High Cycle Fatigue ◽  
Turbine Blades ◽  
Contact Fatigue ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Slip Region ◽  
Set Up ◽  
Good Agreement

Slender turbine blades are susceptible to excitation. Resulting vibrations stress the blade’s fixture to the rotor or stator. In this paper, high cycle fatigue at the edge of contact between blade and rotor/stator of such fixtures is investigated both experimentally and numerically. Plasticity in the contact zone and its effects on e.g. contact tractions, fatigue determinative quantities and fatigue itself are shown to be of considerable relevance. The accuracy of the finite element analysis is demonstrated by comparing the predicted utilizations and slip region widths with data gained from tests. For the evaluation of edge of contact fatigue, tests on simple notched specimens provide the limit data. Predictions on the utilization are made for the edge of contact of a dovetail set-up. Tests with this set-up provide the experimental fatigue limit to be compared to. The comparisons carried out show a good agreement between the experimental results and the plasticity-based calculations of the demonstrated approach.

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