Study on the Induction Quenching Process and Fatigue Testing for Cr-Mo Steel Ball Screw

2018 ◽  
Vol 1145 ◽  
pp. 154-159
Author(s):  
Xia Ding ◽  
Yu Hong Gai ◽  
Bao Min Li ◽  
Mu Sen Li
Keyword(s):  
Fatigue Life ◽  
Fatigue Testing ◽  
Contact Fatigue ◽  
Cooling Water ◽  
Hardened Layer ◽  
Steel Ball ◽  
Ball Screw ◽  
Hardness Distribution ◽  
Fatigue Wear ◽  
Quenching Process

Due to the deficiencies such as shallow hardened layer and short fatigue life of the ball screws treated by the traditional induction quenching process, a new process has been developed. The new induction quenching process has four-turn induction coil. The power of the this process is 150-160kw, feeding speed 270mm/min and the spraying cooling water distance is 35mm. It has been successfully used on the Cr-Mo steel ball screw with a diameter of 80 mm. The microstructure and hardness distribution of the induction hardened layers were investigated by a metallographic microscope and a micro-hardness apparatus. The fatigue life of the ball screw was measured through a constant stress accelerated fatigue test. The degree of fatigue wear on the raceway of the ball screw was analyzed by a field emission scanning electron microscopy (FE-SEM). The experimental results showed that the microstructure and hardness distribution of the hardened layer of the Cr-Mo steel ball screw could satisfy the design requirements of contact fatigue resistance. The fatigue life was longer than the theoretical service life and there was no obvious fatigue wear on the raceway after the fatigue testing. It shows that the safety and reliability of the Cr-Mo steel ball screw fabricated through the new induction quenching process could be guaranteed in practical application.

scholarly journals Rolling Wear of Silicon Nitride Bearing Materials

1990 ◽  
Author(s):  
John W. Lucek
Keyword(s):  
Fatigue Life ◽  
Silicon Nitride ◽  
Failure Modes ◽  
Fatigue Testing ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Performance ◽  
Wear Rates ◽  
Bearing Materials

Rolling-contact fatigue test methods were used to measure the wear performance of several silicon nitride materials. Sintered, hot pressed and hot isostatically pressed materials exhibited wear rates ranging over three orders of magnitude. Hot isostatically pressed materials had the lowest wear rates. Despite the disparity in wear performance, all materials tested had useful rolling-contact fatigue lives compared to steel. Fatigue life estimates, failure modes, and rolling wear performance for theses ceramics are compared to M-50 steel. This work highlights the rapid contact stress reductions that occur due to conformal wear in rolling-contact fatigue testing. Candidate bearing materials with unacceptably high wear rates may exhibit useful fatigue lives. Rolling contact bearing materials must possess useful wear and fatigue resistance. Proper performance screening of candidate bearing materials must describe the failure mode, wear rate, and the fatigue life. Guidelines for fatigue testing methods are proposed.

Analysis of Non-Standard Gear Contact Fatigue Life

2013 ◽  
Vol 300-301 ◽  
pp. 1227-1230
Author(s):  
Ying Qiang Xu ◽  
Jian Hua Zhao ◽  
Zu Heng Shi
Keyword(s):  
Fatigue Life ◽  
Fatigue Testing ◽  
Contact Fatigue ◽  
Testing Time ◽  
The Finite Element Method ◽  
Life Test ◽  
Contact Fatigue Life ◽  
Gear Contact ◽  
Fatigue Life Test ◽  
Test Process

A model of gear contact has been established based on Hertz theory in this thesis, Analysis of non-standard gear contact fatigue life test process . For ha* take 1,1.15,1.25 and c* take 0.25,0.5 respectively ,the gear generates contact fatigue failure, then calculate the meshing ratio under different tooth high coefficients, and gear pairs state with fatigue testing time by the finite element method and orthogonal test. These data are compared with the results of specific experiments verified. They description that tooth height coefficients and headspace coefficients change have a great impact on gear contact fatigue life.

Fatigue Test and Failure Analysis of GD8020×1100 Ball Screw Unit

2014 ◽  
Vol 543-547 ◽  
pp. 3848-3852
Author(s):  
Ye Yan ◽  
Cheng Nan Li ◽  
Yu Hong Gai ◽  
Bao Min Li ◽  
Wei Du ◽  
...  
Keyword(s):  
Fatigue Test ◽  
Contact Fatigue ◽  
Hardened Layer ◽  
Ball Screw ◽  
Surface Wear ◽  
Microscopy Observation ◽  
Normal Contact ◽  
Metallographic Observation ◽  
Hardness Gradient ◽  
Scanning Electron

By means of chemical composition testing, scanning electron microscopy observation, metallographic observation and hardness gradient detection etc, analysis of the typical failure samples from a well-known brand GD8020×1100 ball screw unit in the fatigue test was carried on. Results show that there is no obvious surface wear of the ball screw, showing the normal contact fatigue failure. But severe surface wear happens on the raceway of nut A with obvious flaking and many local cracks; which is the main reason leading to the failure of ball screw unit. So effective measures to avoid earlier failure of the ball screw unit can be put forward by controlling the steel quality strictly and improving the hardness and depth of the hardened layer on the raceway of nut A.

scholarly journals Simulation of the fatigue-wear coupling mechanism of an aviation gear

Friction ◽  
2020 ◽  
Author(s):  
Boyu Zhang ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Yibo Ge
Keyword(s):  
Surface Roughness ◽  
Fatigue Life ◽  
Fatigue Damage ◽  
Contact Fatigue ◽  
Tooth Profile ◽  
Wear Depth ◽  
Fatigue Wear ◽  
Elastic Plastic ◽  
Fatigue Damage Accumulation ◽  
Material Points

AbstractThe contact fatigue of aviation gears has become more prominent with greater demands for heavy-duty and high-power density gears. Meanwhile, the coexistence of tooth contact fatigue damage and tooth profile wear leads to a complicated competitive mechanism between surface-initiated failure and subsurface-initiated contact fatigue failures. To address this issue, a fatigue-wear coupling model of an aviation gear pair was developed based on the elastic-plastic finite element method. The tooth profile surface roughness was considered, and its evolution during repeated meshing was simulated using the Archard wear formula. The fatigue damage accumulation of material points on and underneath the contact surface was captured using the Brown-Miller-Morrow multiaxial fatigue criterion. The elastic-plastic constitutive behavior of damaged material points was updated by incorporating the damage variable. Variations in the wear depth and fatigue damage around the pitch point are described, and the effect of surface roughness on the fatigue life is addressed. The results reveal that whether fatigue failure occurs initially on the surface or sub-surface depends on the level of surface roughness. Mild wear on the asperity level alleviates the local stress concentration and leads to a longer surface fatigue life compared with the result without wear.

scholarly journals MACHINERY LIFE INCREASE BY COMBINED STRENGTHENING

2016 ◽  
Vol 2016 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Д. Соловьёв ◽  
D. Solovev ◽  
Андрей Киричек ◽  
Andrey Kirichek ◽  
Дмитрий Тарасов ◽  
...  
Keyword(s):  
Surface Layer ◽  
Shock Waves ◽  
High Efficiency ◽  
Contact Fatigue ◽  
High Hardness ◽  
Hardened Layer ◽  
Case Hardening ◽  
Fatigue Wear ◽  
Machine Parts ◽  
Large Reserve

The reason of failure of many machine parts is contact fatigue. To increase contact-fatigue wear resistance it is necessary to create a surface layer possessing increased stress-strain properties which are formed by strengthening. The most effective methods of strengthening are those creating a surface layer with simultaneous high hardness and large reserve of plasticity. One of such methods is combined strengthening at which a surface to be strengthened is affected preliminarily by deformation shock waves forming a deep work-hardened layer and then its case hardening is carried out. As a result of this process a strengthened surface layer is formed which consists of hard uniformly strengthened carburized layer and a softer heterogeneously strengthened sublayer alternating hard and soft areas depending on streng-thening modes with shock waves. The operational researches of samples obtained by the offered combined strengthening have shown high efficiency of the method for life increase under conditions of contact cyclic loads which can increase considerably a range of machine parts to be strengthened.

Failure Analysis on the GCr15 Bearing Steel and the 20CrMo Carburized Steel Nuts of the Ball Screw Pair

2014 ◽  
Vol 651-653 ◽  
pp. 29-33 ◽  
Author(s):  
Yu Hong Gai ◽  
Ye Yan ◽  
Cheng Nan Li ◽  
Bao Min Li ◽  
Wei Du ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Fatigue Testing ◽  
Contact Fatigue ◽  
Bearing Steel ◽  
Fatigue Tests ◽  
Ball Screw ◽  
Carburized Steel ◽  
Gcr15 Bearing Steel ◽  
Steel Balls ◽  
Testing Condition

Failure analysis on the GCr15 bearing steel and the 20CrMo carburized steel nuts was performed after two sets of fatigue tests of GD8020×1100 ball screw pair. By means of scanning electron microscopy observation, energy dispersive analysis and microhardness testing, it is found that there is an obvious indentation, slight pitting and microcracks on the raceway of the GCr15 bearing steel nut and shows the characteristics of contact fatigue failure. The nonuniformity of microstructure and the lower carbon and chromium content in the indentation, leading to local lower hardness, account for the nut failure. While the raceway of the 20CrMo carburized steel nut is more rough with scratches caused by the damaged steel balls so as to show the characteristics of wear failure. Therefore there are different failure ways for the different nuts made by different steels and heat treatments under the same fatigue testing condition.

scholarly journals Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4070
Author(s):  
Andrea Karen Persons ◽  
John E. Ball ◽  
Charles Freeman ◽  
David M. Macias ◽  
Chartrisa LaShan Simpson ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Models ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Wearable Sensors ◽  
Fatigue Tests ◽  
Proof Of Concept ◽  
Cycle Fatigue ◽  
Wearable Sensing ◽  
Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

Effect of Grain Flow Orientation on Rolling Contact Fatigue Life of AISI M-50

1982 ◽  
Vol 104 (3) ◽  
pp. 330-334 ◽  
Author(s):  
A. H. Nahm
Keyword(s):  
Fatigue Life ◽  
Flow Line ◽  
Flow Direction ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Vacuum Arc ◽  
Type I ◽  
Grain Flow ◽  
Contact Fatigue Life

Accelerated rolling contact fatigue tests were conducted to study the effect of grain flow orientation on the rolling contact fatigue life of vacuum induction melted and vacuum arc remelted (VIM-VAR) AISI M-50. Cylindrical test bars were prepared from a billet with 0, 45, and 90 deg orientations relative to billet forging flow direction. Tests were run at a Hertzian stress of 4,826 MPa with a rolling speed of 12,500 rpm at room temperature, and lubricated with Type I (MIL-L-7808G) oil. It was observed that rolling contact fatigue life increased when grain flow line direction became more parallel to the rolling contact surface.

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