Tribological characterization of potential crankshaft bearing steels for roller bearing engines

2020 ◽  
pp. 135065012095778
Author(s):  
Aleks Vrček ◽  
Tobias Hultqvist ◽  
Tomas Johannesson ◽  
Pär Marklund ◽  
Roland Larsson
Keyword(s):  
Residual Stress ◽  
Combustion Engine ◽  
Roller Bearing ◽  
Surface Hardness ◽  
Bearing Steel ◽  
Engine Oil ◽  
Limiting Factor ◽  
Surface Fatigue ◽  
Bearing Steels ◽  
Wear Damage

A crankshaft roller bearing internal combustion engine (ICE) offers a five percent or more improvement in overall engine efficiency and, thereby, a reduction in a five percent of CO2 emissions, compared to a plain bearing supported crankshaft. Current forged crankshaft steels represent the limiting factor of the rolling component, therefore, a replacement of the crankshaft steel is required. Apart from this, the tribology of the rolling contacts has been shown to be detrimental when lubricated with current engine oils. Therefore, this paper investigates the tribological performance of potential crankshaft bearing steels, i.e. DIN C56E2 (G55); DIN 50CrMo4 (G50); and DIN 100Cr6 (G3), while utilizing a state-of-the-art low viscosity 0W20 engine oil and under conditions prevalent to ICE. For this, damage mode investigation was performed in a disc-on-disc setup. Based on the results, wear damage of DIN 100Cr6 discs was shown to be dependent on the steel grade of which the counterpart disc was made from and surface hardness difference between both discs. In addition, surface fatigue and wear damage can be completely eliminated by selecting a proper surface roughness and hardness combination. Also, while under an elevated roughness level, engine oil was shown to promote both surface fatigue and wear damage through the work of ZDDP additives, which under extreme conditions can act as an extreme pressure (EP) additive. The residual stress measurements using the XRD technique revealed relatively high compressive residual stresses for G55 and G50 in comparison to G3 steel after surface induction hardening. In addition, no significant changes in residual stress for G55 and G50 were observed after the test. In contrast, relatively high tensile stress was observed for G3 near the surface region. This suggests that the most commonly used 100Cr6 bearing steel, in this case, is the most susceptible to surface fatigue.

Inclination of Principal Residual Stress and the Direction of Cracking in Contact-Fatigued Ball Bearing Steel

1979 ◽  
Vol 23 ◽  
pp. 341-348
Author(s):  
Kikuo Maeda ◽  
Noriyuki Tsushima ◽  
Masatoshi Tokuda ◽  
Hiroshi Muro
Keyword(s):  
Residual Stress ◽  
Ball Bearing ◽  
Roller Bearing ◽  
High Hardness ◽  
Bearing Steel ◽  
Rolling Contact ◽  
Lubricating Oil ◽  
Peeling Test ◽  
Surface Fatigue ◽  
Ball Bearing Steel

Peeling is a surface fatigue failure of a roller bearing that consists of many shallow pits less than 10 pm in depth and cracks that link the pits. Peeling occurs rather easily on a smooth Surface when in contact with a rough surface under insufficient thickness of the lubricating oil film.X-ray residual stress measurements on and under the contact surface after a peeling test revealed that the 2θ versus sin2ψ curve is not linear and that it curves depending upon the rolling contact condition and especially upon the existence of slip. Nonlinearity of the 2θ-sin2ψ) curve has been reported by Wakabayashi in a study of residual stress accompanying the grinding of soft steel and by Faninger in a study of residual stress due to rolling contact with annealed steel, but hot in the case of high hardness steel such as ball bearing steel. No complete explanation of this non-linearity has been made as yet.

scholarly journals Micro-Pitting and Wear Assessment of PAO vs Mineral-Based Engine Oil Operating under Mixed Lubrication Conditions: Effects of Lambda, Roughness Lay and Sliding Direction

Lubricants ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 42 ◽  
Author(s):  
Aleks Vrček ◽  
Tobias Hultqvist ◽  
Yannick Baubet ◽  
Marcus Björling ◽  
Pär Marklund ◽  
...  
Keyword(s):  
Bearing Steel ◽  
Mixed Lubrication ◽  
Operating Conditions ◽  
Engine Oil ◽  
Engine Oils ◽  
Rolling Contacts ◽  
Steel Surfaces ◽  
Wear Damage ◽  
Lubrication Conditions ◽  
Ball On Disc

Under certain operating conditions, rolling contacts have been shown to experience some challenges when lubricated with engine oils containing zinc dialkyldithophosphate (ZDDP) anti-wear additive. In order to better understand the main damage mechanisms during various operating conditions, further studies are needed. This article studies micro-pitting and wear damages of bearing steel surfaces under mixed lubrication conditions in a ball-on-disc setup, lubricated with different engine oils. Based on the results, micro-pitting and wear damage is shown to be highly case-dependent. In general, PAO-based engine oil tends to eliminate micro-pitting damage compared to mineral-based engine oil at less severe lubricating conditions. Moreover, a critical lambda was found for both oils, where the highest micro-pitting damage was observed.

scholarly journals Effect of the Al2O3 Content in the Slag on the Chemical Reactions and Nonmetallic Inclusions during Electroslag Remelting

2020 ◽  
Vol 51 (5) ◽  
pp. 1904-1911 ◽  
Author(s):  
Reinhold S. E. Schneider ◽  
Manuel Molnar ◽  
Gerald Klösch ◽  
Christopher Schüller
Keyword(s):  
Chemical Composition ◽  
Service Life ◽  
Nonmetallic Inclusions ◽  
Roller Bearing ◽  
Bearing Steel ◽  
Electroslag Remelting ◽  
Al2o3 Content ◽  
Spinel Type ◽  
Bearing Steels ◽  
Equilibrium Reactions

Abstract The service life of roller bearings is extremely sensitive to large and hard nonmetallic inclusions (NMIs), requesting the highest standards in their production. To determine the metallurgical possibilities, the effect of Al2O3 contents between 0 and 33 pct in the remelting slag was investigated by remelting a roller bearing steel in an experimental electroslag remelting (ESR) plant. Thereby, changes in the chemical composition of the materials (electrode vs ingots) and in the remelting slag during remelting, as well as the amount and composition of the NMIs prior to and after remelting, were investigated. Changes in the chemical composition can largely be explained by equilibrium reactions between the slag and the metal, thereby low Al contents in the remelted materials could only be achieved with the lowest Al2O3 contents in the slag. Furthermore, higher Al2O3 contents in the slag also lead to higher oxygen and sulfur contents in the steel as well as higher amounts of NMIs after remelting. The composition of the NMIs changed from alumina type for high Al2O3 contents to spinel type and other mixed MgO-SiO2 oxides for low Al2O3 contents. The results indicate solutions for the production of bearing steels with the lowest amounts of undesired large and hard NMIs.

scholarly journals NEW BEARING STEEL FOR HIGH-SPEED APPLICATIONS

2021 ◽  
Vol 2021 (6) ◽  
pp. 5334-5339
Author(s):  
CHRISTIAN BRECHER ◽  
◽  
STEPHAN NEUS ◽  
MARCUS GAERTNER ◽  
LEONARDO CATANA ◽  
...  
Keyword(s):  
High Speed ◽  
Rolling Bearing ◽  
Bearing Steel ◽  
Performance Limits ◽  
Test Rig ◽  
Good Resistance ◽  
Surface Fatigue ◽  
Bearing Steels ◽  
Spindle Bearing ◽  
Contact Pressures

The requirements for speed suitability and fatigue strength of motor spindle bearings are constantly increasing. These challenges can be met by further developing the spindle bearings, e.g. by using higher-performance bearing steels. In the following, the experimental investigation results of a spindle bearing made of a new raceway steel tested on a high-speed rolling bearing test rig are presented. Spindle bearings of the type 7008 (hybrid execution) were tested in an endurance run at a rotational speed of 46 krpm and 3 kN axial load. The operating behaviour was validated based on the bearing outer ring temperature and the vibration behaviour. Microscope analysis of the raceways after the test shows that the new steel has good resistance to micropitting and surface fatigue. The calculated contact pressures, wear parameter and lifetime for the bearings in the tests show that the performance limits of spindle bearings are significantly higher than initially assumed.

Applications of vibro-acoustic measurement and analysis in conjunction with tribological parameters to assess surface fatigue wear developed in the roller-bearing system

2021 ◽  
pp. 135065012098246
Author(s):  
Shashikant Pandey ◽  
Muniyappa Amarnath
Keyword(s):  
Roller Bearing ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Stribeck Curve ◽  
Fatigue Wear ◽  
Surface Fatigue ◽  
Rolling Element ◽  
Measurement And Analysis ◽  
Contact Surfaces ◽  
Bearing System

Rolling-element bearings are the most commonly used components in all rotating machinery. The variations in the operating conditions such as an increase in the number of operating cycles, load, speed, service temperature, and lubricant degradation result in the development of various defects such as pitting, spalling, scuffing, scoring, etc. The defects that appeared on rolling contact surfaces cause surface deterioration and change in the vibration and sound levels of the bearing system. The present experimental investigations are aimed at assessing the surface fatigue wear that appears on the contact surfaces of roller bearings. The studies considered the estimation of specific film thickness, analysis of surface fatigue wear developed on the rolling-element surfaces, surface roughness analysis, grease degradation analysis using Fourier transform infrared radiation, and vibration and sound signal measurement and analysis. The results obtained from the experimental investigation provide a good correlation between surface wear, vibration, and sound signals with a transition in the lubrication regimes in the Stribeck curve.

Study on bearing stiffness characteristics with residual stress in carburized layer

2020 ◽  
pp. 095440622096079
Author(s):  
Junshuai Liang ◽  
Ning Li ◽  
Jingyu Zhai ◽  
BaoGang Wen ◽  
Qingkai Han ◽  
...  
Keyword(s):  
Residual Stress ◽  
Contact Stiffness ◽  
Roller Bearing ◽  
High Load ◽  
Axial Stiffness ◽  
Fe Model ◽  
Low Load ◽  
Bearing Stiffness ◽  
Carburized Layer ◽  
Stiffness Characteristics

In this study, a layering method of carburized ring is presented. A finite element (FE) model for analyzing bearing stiffness characteristics is established considering the residual stress in the carburized layer. The residual stress in the carburized layer of a double-row conical roller bearing is tested and the influence of the distribution of residual stress in carburized layer on the bearing stiffness is investigated. Results show that the residual stress in the carburized layer increases the contact stiffness of the bearing by 5% in the low-load zone and 3% in the high-load zone. The radial stiffness of the bearing is increased by 5% in the low-load zone and 3% in the high-load zone. The axial stiffness is increased by 6%, and the angular stiffness increased by 4%. The larger the thickness of the carburized layer, the greater the residual compressive stress in the carburized layer, the deeper the position of the maximum residual stresses in the carburized layer will lead to the greater stiffness of the bearing.

scholarly journals Quantitative Analysis of Inclusion Engineering on the Fatigue Property Improvement of Bearing Steel

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 476 ◽  
Author(s):  
Chao Gu ◽  
Min Wang ◽  
Yanping Bao ◽  
Fuming Wang ◽  
Junhe Lian
Keyword(s):  
Fatigue Life ◽  
Quantitative Analysis ◽  
Critical Size ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Fatigue Property ◽  
Bearing Steel ◽  
Fatigue Properties ◽  
Bearing Steels ◽  
Inclusion Distribution

The fatigue property is significantly affected by the inner inclusions in steel. Due to the inhomogeneity of inclusion distribution in the micro-scale, it is not straightforward to quantify the effect of inclusions on fatigue behavior. Various investigations have been performed to correlate the inclusion characteristics, such as inclusion fraction, size, and composition, with fatigue life. However, these studies are generally based on vast types of steels and even for a similar steel grade, the alloy concept and microstructure information can still be of non-negligible difference. For a quantitative analysis of the fatigue life improvement with respect to the inclusion engineering, a systematic and carefully designed study is still needed to explore the engineering dimensions of inclusions. Therefore, in this study, three types of bearing steels with inclusions of the same types, but different sizes and amounts, were produced with 50 kg hot state experiments. The following forging and heat treatment procedures were kept consistent to ensure that the only controlled variable is inclusion. The fatigue properties were compared and the inclusions that triggered the fatigue cracks were analyzed to deduce the critical sizes of inclusions in terms of fatigue failure. The results show that the critical sizes of different inclusion types vary in bearing steels. The critical size of the spinel is 8.5 μm and the critical size of the calcium aluminate is 13.5 μm under the fatigue stress of 1200 MPa. In addition, with the increase of the cleanliness of bearing steels, the improvement of fatigue properties will reach saturation. Under this condition, further increasing of the cleanliness of the bearing steel will not contribute to the improvement of fatigue property for the investigated alloy and process design.

Failure Analysis of Engine Valves and its Performance Evaluation under Various Titanium Based Composite Coatings Using FE Analysis

2021 ◽  
Vol 903 ◽  
pp. 79-89
Author(s):  
R. Sundara Rao ◽  
K. Hemachandra Reddy ◽  
Ch.R. Vikram Kumar
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Combustion Engine ◽  
Mechanical Load ◽  
Composite Coatings ◽  
Surface Hardness ◽  
Engine Operation ◽  
Engine Valve ◽  
Simulation Results ◽  
Two Wheeler

In an internal combustion engine poppet valve is the crucial component which often opens and closes, thereby regulating gas flow in an engine cylinder. During engine operation, the valve is exposed to high temperature gases (thermal load) along with spring and cam loads (mechanical load). Due to high temperatures and fatigue loads, the valves are subjected to metallurgical changes and leads to failure. In order to resist these extreme conditions of high temperature and mechanical loads, the engine valve should possess special properties such as high surface hardness, a good amount of thermal conductivity, and fatigue strength. In this work, the reasons for the failure of two wheeler engine valve were evaluated and found that failure takes place due to change in the chemical composition mainly due to thermal diffusion at the interfaces. Thermal barrier coatings on the valve surface arrest the temperature load and increase its life. In this work, the performance of various titanium based composite coatings, i.e., TiN, TiC, TiC-Al2O3, TiCN, TiAlN, TiN- Al2O3, DLC, and uncoated valves of two wheeler engine was simulated using Finite Element Analysis. The simulation results indicated that coated valves have less thermal and fatigue loading and have more life than the uncoated valve. The Finite element simulation results of both coated and uncoated valves are presented and analyzed in this paper.

Sign in / Sign up

Export Citation Format

Share Document