Experimental Research on the performance of HIGH temperature bearing steel Cr4Mo4V

2021 ◽  
Vol 14 ◽  
Author(s):  
Zenan Chu ◽  
Qiang He
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Friction Coefficient ◽  
Three Dimensional ◽  
Hardness Test ◽  
Surface Friction ◽  
Bearing Steel ◽  
Metallographic Analysis ◽  
Element Analysis ◽  
Friction Resistance

Background:: The Cr4Mo4V steel is widely used in high temperature bearings because of its excellent high temperature performance. According to the research status of Cr4Mo4V at home and abroad, this paper explores its mechanical properties and friction properties at high temperatures. Objective:: To characterize the composition, microstructure and properties of Cr4Mo4V steel and to explore its tensile properties, hardness and friction properties at high temperature. Methods: Many methods are adopted, such as chemical element analysis, metallographic analysis, hardness test, tensile test, damping test, friction test and so on. Results: The microstructure of Cr4Mo4V is tempered martensite. The hardness and maximum tensile strength of Cr4Mo4V decrease with temperature increasing. The grain of the Cr4Mo4V steel after heating gets refined and the grain boundary increases. At room temperature, the surface friction coefficient and wear rate of Cr4Mo4V steel decreases. Moreover, Cr4Mo4V steel-ceramic ball shows the best friction resistance. At high temperature, the friction coefficient and the wear of Cr4Mo4V steel firstly decrease with temperature increasing and then increase sharply at 200°C. Conclusion: With the increase of temperature, the hardness, breaking force and tensile strength of Cr4Mo4V bearing steel decrease, whereas the friction property increases. By analyzing the three-dimensional morphology of different wear samples, the optimal working temperature of Cr4Mo4V steel for bearing is 200°C.

Nonlinear Finite Element Analysis of Super-Long Pile and Soil Interaction in Soft Soil

2011 ◽  
Vol 201-203 ◽  
pp. 1601-1605 ◽  
Author(s):  
Shang Ping Chen ◽  
Wen Juan Yao ◽  
Sheng Qing Zhu
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Soft Soil ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Element Analysis ◽  
Friction Resistance ◽  
Tip Resistance ◽  
Side Friction

In this paper, a nonlinear three-dimensional finite element model for super-long pile and soil interaction is established. In this model, contact elements are applied to simulate the nonlinear behavior of interaction of super-long pile and soil. A nonlinear elastic constitutive model for concrete is employed to analyze stress-strain relation of pile shaft under the axial load and the Duncan-Chang’s nonlinear constitutive model is used to reflect nonlinear and inelastic properties of soil. The side friction resistance, axial force, pile-tip resistance, and developing trend of soil plastic deformation are obtained and compared with measured results from static load tests. It is demonstrated that a super-long pile has the properties of degradation of side friction resistance and asynchronous action between side and pile-tip resistance, which is different from piles with a short to medium length.

A High Temperature, Fast Switching SiC Multi-chip Power Module (MCPM) for High Frequency (> 500 kHz) Power Conversion Applications

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000056-000060 ◽  
Author(s):  
Z. Cole ◽  
B. S. Passmore ◽  
B. Whitaker ◽  
A. Barkley ◽  
T. McNutt ◽  
...  
Keyword(s):  
High Temperature ◽  
High Frequency ◽  
Power Conversion ◽  
Three Dimensional ◽  
Boost Converter ◽  
Switching Frequency ◽  
Power Module ◽  
Element Analysis ◽  
Switching Characteristics ◽  
Three Dimensional Finite Element

In high frequency power conversion applications, the dominant mechanism attributed to power loss is the turn-on and -off transition times. To this end, a full-bridge silicon carbide (SiC) multi-chip power module (MCPM) was designed to minimize parasitics in order to reduce over-voltage/current spikes as well as resistance in the power path. The MCPM was designed and packaged using high temperature (> 200 °C) materials and processes. Using these advanced packaging materials and devices, the SiC MCPM was designed to exhibit low thermal resistance which was modeled using three-dimensional finite-element analysis and experimentally verified to be 0.18 °C/W. A good agreement between the model and experiment was achieved. MCPMs were assembled and the gate leakage, drain leakage, on-state characteristics, and on-resistance were measured over temperature. To verify low parasitic design, the SiC MCPM was inserted into a boost converter configuration and the switching characteristics were investigated. Extremely low rise and fall times of 16.1 and 7.5 ns were observed, respectively. The boost converter demonstrated an efficiency of > 98.6% at 4.8 kW operating at a switching frequency of 250 kHz. In addition, a peak efficiency of 96.5% was achieved for a switching frequency of 1.2 MHz and output power of 3 kW.

scholarly journals A Three-Dimensional Elastic-Plastic Contact Analysis of Vickers Indenter on a Deep Drawing Quality Steel Sheet

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2153 ◽  
Author(s):  
Tomasz Trzepiecinski ◽  
Hirpa G. Lemu
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Deep Drawing ◽  
Three Dimensional ◽  
Hardness Test ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Quality Steel ◽  
Vickers Indenter ◽  
Pile Up

Three-dimensional finite element-based numerical analysis of Vickers indenter hardness test was conducted to investigate the effect of frictional conditions and material anisotropy on indentation results of deep drawing quality steel sheets. The strain hardening properties and Lankford’s coefficient were determined through the uniaxial tensile tests. The numerical computations were carried out using ABAQUS nonlinear finite element (FE) analysis software. Numerical simulations taken into account anisotropy of material described by Hill (1948) yield a criterion. The stress and strain distributions and loading–unloading characteristics were considered to study the response of the material. It was found that the hardness values seemed to be influenced by the value of the friction coefficient due to the pile-up phenomenon observed. The increasing of the friction coefficient led to a decrease of the pile-up value. Moreover, the width of the pile-ups differed from each other in the two perpendicular directions of measurement. Frictional conditions did not significantly affect the maximum force and the character of load–displacement curves. Frictional regime between the indenter and workpiece caused that the region of maximum residual stresses to be located in the subsurface.

3D Finite Element Analysis of Prestressed Cutting

2012 ◽  
Vol 591-593 ◽  
pp. 766-770 ◽  
Author(s):  
Rui Tao Peng ◽  
Fang Lu ◽  
Xin Zi Tang ◽  
Yuan Qiang Tan
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Bearing Steel ◽  
Arbitrary Lagrangian Eulerian ◽  
Machined Surface ◽  
Element Analysis ◽  
Simulation Techniques ◽  
Ale Formulation

In order to reveal the adjustment principle of prestressed cutting on the residual stress of hardened bearing steel GCr15, a three-dimensional thermal elastic-viscoplastic finite element model was developed using an Arbitrary Lagrangian Eulerian (ALE) formulation. Several key simulation techniques including the material constitutive model, constitutive damage law and contact with friction were discussed, simulation of chip formation during prestressed cutting was successfully conducted. At the prestresses of 0 MPa, 341 MPa and 568 MPa, distributions of residual stress on machined surface were simulated and experimentally verified. The results indicated that residual compressive stress on machined surface were achieved and actively adjusted by utilizing the prestressed cutting method; meanwhile, within the elastic limit of bearing steel material, the higher applied prestress leads to the more prominent compressive residual stress in the surface layer and subsequently the higher fatigue resistance of the part.

The Reliability Prediction of HTR’s Graphite Component in Various Temperature and Neutron Dose Levels

2013 ◽  
Author(s):  
Xiang Fang ◽  
Haitao Wang ◽  
Xingtuan Yang ◽  
Suyuan Yu
Keyword(s):  
High Temperature ◽  
Neutron Irradiation ◽  
Three Dimensional ◽  
Reactor Core ◽  
Neutron Dose ◽  
Element Analysis ◽  
The Core ◽  
Three Dimensional Finite Element ◽  
Dose Levels ◽  
The Impact

In high temperature gas-cooled reactors (HTRs), graphite is used as the main structure material. The side reflecter of the reactor core is composed by a pile of graphite bricks. In real operational condition of the reactor, both high temperature and fast neutron irradiation have great effect on the behavior of graphite components. The non-uniform distribution of temperature and neutron dose cause obvious stress accumulation, which greatly affects the security and reliability of the graphite components. In addition, high temperature and neutron irradiation make the properties of graphite change in evidence, and the changes are not linear. Such changes must be considered and simulated in the calculation, in order to predict the stress concentration condition and the reliability of the graphite brick correctly. A FORTRAN code based on user subroutines of MSC.MARC is developed in INET in order to perform three-dimensional finite element analysis of irradiated behavior of the graphite components for the HTRs. In this paper, the stress level and failure probability of graphite components are calculated and obtained under different in-core temperatures and neutron dose levels of the core side of brick. 400°C, 500°C, 600°C and 700°C are selected as the core side temperature, while the range of neutron dose is 0 to 1022n cm-2 (EDN). Different constitutive laws are used in stress analysis procedure. The impact of different temperature and neutron dose levels are discussed.

Elasto-Plastic Finite Element Analysis of Three-Dimensional Pure Rolling Contact Above the Shakedown Limit

1991 ◽  
Vol 58 (2) ◽  
pp. 347-353 ◽  
Author(s):  
S. M. Kulkarni ◽  
G. T. Hahn ◽  
C. A. Rubin ◽  
V. Bhargava
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Kinematic Hardening ◽  
Three Dimensional ◽  
Bearing Steel ◽  
Complex Stress State ◽  
Rolling Contact ◽  
Stress Strain ◽  
Element Analysis ◽  
Shakedown Limit

This paper describes calculations for repeated, frictionless, three-dimensional rolling contact, for a relative peak pressure (po/k) of 6.0 (above the shakedown limit) for a circular contact patch. This analysis was carried out for two material responses, elastic-perfectly plastic (EPP) and elastic-linear-kinematic-hardening plastic (ELKP), using the elasto-plastic finite element model developed earlier. The ELKP material parameters are those appropriate for hardened bearing steel. Frictionless three-dimensional rolling contact is simulated by repeatedly translating a Hertzian pressure distribution across the surface of an elasto-plastic half space. The half space is represented by a finite mesh with elastic boundaries. The paper describes the complex stress state existing in the half space and the attending plasticity, as the load translates. The calculations present the distortion of the rim, the residual stress-strain distributions, stress-strain histories, and the cyclic plastic strain increments in the vicinity of the contact. Compared with the analyses at the shakedown limit, higher residual stresses and strains are observed.

Thermal Stress and Failure Location Analysis for Through Silicon via in 3D Integration

2015 ◽  
Vol 32 (1) ◽  
pp. 47-53 ◽  
Author(s):  
H.-Y. Tsai ◽  
C.-W. Kuo
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
High Temperature ◽  
Stress Distribution ◽  
Surface Area ◽  
Dielectric Material ◽  
Three Dimensional ◽  
3D Integration ◽  
Element Analysis ◽  
Through Silicon Via

AbstractThrough silicon via (TSV) is the critical structure for three dimensional (3D) integration, which provides vertical interconnection between stacking dies. In TSV structure, large coefficient differences of thermal expansion exist between silicon substrate, dielectric material, and filled metal. Due to the large thermal mismatch, the high thermal stress occurring at the interface of different materials would result in delamination. Therefore, thermal-mechanical reliability is a key issue for 3D integration. In this study, we investigated the thermal-mechanical stress distribution of TSV under the condition of the accelerated thermal cycling loading by finite element analysis based on a 3D model of TSV structure. Due to the thermal expansion, that the TSV structure squeezed the surface area between TSVs at a high temperature resulted in compressive stresses at the surface area between TSVs. Therefore, a proper distance between the stress-sensitive device and the TSV should be kept. The stress analysis shows that the maximum thermal stress occurs in the outside region of TSV interface and in the annular region of TSV at a high temperature and at a low temperature, respectively. This study helps to obtain a clear thermal stress distribution of TSV and possible failure regions can be determined.

Study on the Friction Factor and High-Temperature Friction Resistance of Semi-Metal Frictional Materials

2016 ◽  
Vol 693 ◽  
pp. 629-637 ◽  
Author(s):  
Yue Wang ◽  
Yuan Kang Zhou ◽  
Hua Wei Nie
Keyword(s):  
Thermal Decomposition ◽  
Tensile Strength ◽  
High Temperature ◽  
Friction Factor ◽  
Friction Stress ◽  
Friction Resistance ◽  
Cashew Nut ◽  
Study Results ◽  
Cashew Nut Shell ◽  
Functional Components

The orthogonal experimental study is carried out to study the Incorporation of different proportion of functional components and the effect on tribological performance among semi-metallic friction materials. A test is conducted for each sample on XXD-MSM constant speed tester in accordance with Brake Linings for Automobiles (GB5763-2008). The friction factor and high-temperature abrasion resistance properties are evaluated along with the obtaining of optimal formula, and the mechanism of affecting the tribological properties is analyzed on the worn surfaces by using a scanning electron microscope (SEM). The study results indicate that the high-temperature friction stability could be deeply affected by the adequate content of steel fiber, Kevlar pulp, potassium hexatitanate whisker and cashew nut shell. The mechanism of High-temperature tribological behaviors are the thermal decompositions. The thermal decomposition of organic matter might greatly weakened the bonding effect. The thermal decomposition of tribo-film fall off as lamellar chip under the effect of friction stress. The addition level of nanoparticles is 3%, the sample’s tensile strength, tensile strength, hardness index and noise level are better. If the modified resin is further applied, this formula can be close to the index of excellent Chinese industrial product JF04-20.

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