scholarly journals Crack growth rates and microstructure feature of initiation region for very-high-cycle fatigue of a high-strength steel

2018 ◽  
Vol 41 (8) ◽  
pp. 1717-1732 ◽  
Author(s):  
Yuanpei Hu ◽  
Chengqi Sun ◽  
Youshi Hong
Keyword(s):  
Crack Growth ◽  
Growth Rates ◽  
High Strength Steel ◽  
High Cycle Fatigue ◽  
High Strength ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Crack Growth Rates ◽  
Very High

scholarly journals Very High Cycle Fatigue of Butt-Welded High-Strength Steel Plate

Metals ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 103 ◽  
Author(s):  
Hyunho Yeom ◽  
Byungjoo Choi ◽  
Taeho Seol ◽  
Moongu Lee ◽  
Yongho Jeon
Keyword(s):  
High Strength Steel ◽  
High Cycle Fatigue ◽  
Steel Plate ◽  
High Strength ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Very High

scholarly journals The influence of tension mean stress to the crack initiation process at the very high cycle fatigue regime for a high strength steel

2018 ◽  
Vol 165 ◽  
pp. 20001
Author(s):  
Thomas Rohm ◽  
Karl-Heinz Lang ◽  
Marcus Korn
Keyword(s):  
Crack Initiation ◽  
High Strength Steel ◽  
High Cycle Fatigue ◽  
High Strength ◽  
Mean Stress ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Initiation Process ◽  
Incremental Step ◽  
Very High

Strain controlled tests were performed on a high strength steel to investigate the influence of tension mean stress to the crack initiation process at the very high cycle fatigue regime. It is supposed that the variation of stress the state in the vicinity of a non-metallic inclusion results in a change to the energy transferred to the surrounding metallic matrix. To prove this, incremental step tests on cylindrical specimen were realized in which the tension mean stress was stepwise increased. It could be verified that the hysteresis area, which is a criterion of the work transferred to the specimen, decreases with increasing tension mean stress. The test results provide a reasonable physical model to estimate the influence of tension mean stress to the crack initiation process in the very high cycle fatigue regime.

A Study on Very High Cycle Fatigue Property of High Strength Steel for Particular Use as Medical Tablets Compressing Punches

2015 ◽  
Vol 664 ◽  
pp. 221-230 ◽  
Author(s):  
Tatsuo Sakai ◽  
Akio Kokubu ◽  
Shoichi Kikuchi ◽  
Hiroshi Tanaka ◽  
Fumiharu Ikai ◽  
...  
Keyword(s):  
High Strength Steel ◽  
High Cycle Fatigue ◽  
Low Cost ◽  
Fatigue Property ◽  
High Strength ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Very High Frequency ◽  
Very High Cycle Fatigue ◽  
Very High

In the fabrication process of medicine tablets, working speed of the tablet compressing is an important factor to realize the high fabricating efficiency together with the low cost. Thus, a number of loadings would be applied with very high frequency to tips of a couple of compressing punches. Sometimes, the tablet compressing speed exceeds 150 tablets per second. Due to such a circumstance, the very high cycle loadings are applied to the tips of the compressing punches making medicine tablets. The high strength steel of KNS-ES was specially designed and fabricated for the particular use as the compressing punches. In this study, very high cycle fatigue tests were performed in the loading type of rotating bending in order to obtain the fundamental S-N property of this steel. Based on experimental results, the S-N property in giga-cycle regime was discussed including the effect of the residual stress on the S-N properties. Consequently, the duplex S-N curves were clearly found, but the surface-induced fractures were often found in the fatigue data belonging to the second S-N curve in the longer life region.

scholarly journals Effects of Loading Frequency and Loading Type on High-Cycle and Very-High-Cycle Fatigue of a High-Strength Steel

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1456 ◽  
Author(s):  
Yuanpei Hu ◽  
Chengqi Sun ◽  
Jijia Xie ◽  
Youshi Hong
Keyword(s):  
High Strength Steel ◽  
High Cycle Fatigue ◽  
Control Volume ◽  
High Strength ◽  
Frequency Effect ◽  
Loading Frequency ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Very High ◽  
Loading Type

High-cycle and very-high-cycle fatigue tests via rotary bending (52.5 Hz), electromagnetic resonance (120 Hz) axial cycling, and ultrasonic (20 kHz) axial cycling were performed for a high-strength steel with three heat treatment conditions, and the effects of loading frequency and loading type on fatigue strength and fatigue life were investigated. The results revealed that the loading frequency effect is caused by the combined response of strain rate increase and induced temperature rise. A parameter η was proposed to judge the occurrence of loading frequency effect, and the calculated results were in agreement with the experimental data. In addition, a statistical method based on the control volume was used to reconcile the effect of loading type, and the predicted data were consistent with the experimental results.

Very High Cycle Fatigue Behavior and Thermographic Analysis of High Strength Steel

2010 ◽  
Vol 118-120 ◽  
pp. 948-951
Author(s):  
Chuang Shao ◽  
Claude Bathias ◽  
Danièle Wagner ◽  
Hua Tao
Keyword(s):  
Crack Initiation ◽  
High Strength Steel ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
High Strength ◽  
Cycle Fatigue ◽  
Subsurface Crack ◽  
Very High Cycle Fatigue ◽  
Very High

Very high cycle fatigue behavior of high strength steel, were investigated using ultrasonic fatigue testing equipment at 20 kHz up to 109cycles. S-N curves at room temperature with different stress ratio (R=0.01 and R=0.1) was determined. The experimental results show that fatigue strength decrease with increasing number of cycles between 105 and 109. SEM examination of fracture surface reveals that fatigue damage was governed by the formation of cracks, and subsurface crack initiation was in the very long life range. The results shown that the portions of life attributed to subsurface crack initiation between 107 and 109 cycles are 99%.

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