scholarly journals Giga-Cycle Fatigue Behavior of the Nuclear Structure of 316L Weldments

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhihong Xiong ◽  
Engao Peng ◽  
Lianghua Zeng ◽  
Qirong Xu
Keyword(s):  
Fatigue Strength ◽  
Arc Welding ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Laser Beam Welding ◽  
Fatigue Loading ◽  
Testing System ◽  
Cycle Fatigue ◽  
Gas Tungsten Arc ◽  
Ultrasonic Fatigue

Some components made of 316L stainless steel in nuclear reactors are connected by welding, and these are under giga-cycle fatigue loading. Therefore, the giga-cycle fatigue behavior of 316L weldments, which are fabricated by Laser Beam Welding (LBW) and Gas Tungsten Arc Welding (GTAW), were investigated using an ultrasonic fatigue testing system. The results indicate that the fatigue strength of LBW-made weldments is almost the same as that of GTAW-made weldments even though the microstructure and mechanical properties of the weldments are different. For the LBW-made specimens, the LBW-induced internal pores with a diameter range of about 89–270 μm were observed in the fracture surface. However, an obvious decrease in fatigue life was not observed in such cases. For the GTAW-made specimens, the quality requirement of the weld seam has to be more strict to prevent fatigue strength from decreasing. The fatigue failure mode of the GTAW-made specimens is the same as that of LBW-made specimens in the high-cycle fatigue regime but different in the giga-cycle fatigue regime.

scholarly journals Recent Advances in Very High Cycle Fatigue Behavior of Metals and Alloys—A Review

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1200
Author(s):  
Ashutosh Sharma ◽  
Min Chul Oh ◽  
Byungmin Ahn
Keyword(s):  
Crack Initiation ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Simulation Studies ◽  
Cycle Fatigue ◽  
Future Directions ◽  
Very High Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Very High

We reviewed the research and developments in the field of fatigue failure, focusing on very-high cycle fatigue (VHCF) of metals, alloys, and steels. We also discussed ultrasonic fatigue testing, historical relevance, major testing principles, and equipment. The VHCF behavior of Al, Mg, Ni, Ti, and various types of steels were analyzed. Furthermore, we highlighted the major defects, crack initiation sites, fatigue models, and simulation studies to understand the crack development in VHCF regimes. Finally, we reviewed the details regarding various issues and challenges in the field of VHCF for engineering metals and identified future directions in this area.

Low Tension-Tension Cycle Fatigue Properties of 301 Stainless Steel Thin Sheets

2013 ◽  
Vol 351-352 ◽  
pp. 887-891
Author(s):  
Shi Ming Cui ◽  
Rui Dong Wang ◽  
Yong Jie Liu ◽  
Tao Long ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Stress Ratio ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Fatigue Properties ◽  
Testing System ◽  
Loading Frequency ◽  
Thin Sheets ◽  
Cycle Fatigue ◽  
Low Tension

By using of a micro mechanical fatigue testing system, low tension-tension cycle fatigue properties of 301 stainless steel thin sheets with a thickness of 0.1 mm were studied. The effects of loading frequency and stress ratio were considered in the tests. The results show the S-N curves descend continuously in the low cycle regime. Cyclic σ-N curve was obtained according to the traditional fatigue theory. It agrees well with the experimental data, showing that the traditional fatigue research methods are also suitable to describe thin sheets in a certain extent. With the increase of loading stress ratio, the fatigue strength of thin sheets is increased. There is an evident effect of frequency on the fatigue behavior of the thin sheets.

Influence of Defects on High Cycle Fatigue Response of Ti45Nb Biocompatible Alloy

2016 ◽  
Vol 258 ◽  
pp. 337-340 ◽  
Author(s):  
Mitra Delshadmanesh ◽  
Golta Khatibi ◽  
Martin Lederer ◽  
Michael Zehetbauer ◽  
Herbert Danninger
Keyword(s):  
High Cycle Fatigue ◽  
Surface Defects ◽  
Fatigue Testing ◽  
Stress Amplitude ◽  
Testing System ◽  
Cycle Fatigue ◽  
Early Failure ◽  
Element Analysis ◽  
Notch Geometry ◽  
Ultrasonic Fatigue

The high cycle fatigue response of Ti-45Nb alloy was investigated by using an ultrasonic fatigue testing system. The effect of notch geometry on the fatigue response was studied on samples with different circumferential grooves. The experiments showed a decrease of fatigue notch sensitivity with decreasing the notch radius. Finite element analysis (FEA) was conducted for calculation of the stress distribution in the samples and interpretation of the experimental results. Further, the lifetime of the alloy showed a strong dependency on the location of the defects and microstructural inhomogeneities. It was observed that at the same stress amplitude, early failure was caused by surface defects, while those with a longer lifetime failed due to cracks originating from internal flaws.

Study on Bending Ultrasonic Fatigue Behavior of Sinter-Hardened Fe-2Cu-2Ni-1Mo-1C Materials Prepared by Warm Compaction

2010 ◽  
Vol 638-642 ◽  
pp. 1848-1853 ◽  
Author(s):  
Zhi Yu Xiao ◽  
Ling Zhou ◽  
Yuan Xun Shen ◽  
Tungwai Leo Ngai ◽  
Yuan Yuan Li
Keyword(s):  
Fatigue Strength ◽  
Crack Propagation ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Bending Fatigue ◽  
Warm Compaction ◽  
Ultrasonic Fatigue ◽  
Number Of Cycles ◽  
Rupture Mode

Bending fatigue behavior of a sinter-hardened high density (7.4 g/cm3) Fe-2Cu-2Ni-1Mo-1C material fabricated by die-wall lubricated warm compaction of partially-diffuse alloyed powder was studied by bending ultrasonic fatigue testing. Results showed that fatigue strength decreases continuously with the increasing number of cycles. The fatigue failure yet occurs in the regime of exceeding 107 cycles and exhibits no traditional horizontal plateau between 106 and 107 cycles. Fatigue strength was 194 MPa, 239 MPa and 293 MPa at 108, 107 and 106 cycles respectively. Scanning electron microscopy revealed that cracks initiated from large pores on the surface and from pore clusters near the sub-surface. The fatigue cracks initiated both at single and multiple sites. Crack propagation was mainly in a trans-crystalline rupture mode. Fatigue striation and cleavage plane were observed in the crack propagation region and dimples were observed in the fracture zones.

Ultrasonic Fatigue of CFRP - Experimental Principle, Damage Analysis and Very High Cycle Fatigue Properties

2017 ◽  
Vol 742 ◽  
pp. 621-628 ◽  
Author(s):  
Dominic Weibel ◽  
Frank Balle ◽  
Daniel Backe
Keyword(s):  
Carbon Fiber ◽  
Matrix Composite ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Polyphenylene Sulfide ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Very High

Structural aircraft components are often subjected to more than 108 loading cycles during their service life. Therefore the increasing use of carbon fiber reinforced polymers (CFRP) as primary lightweight structural materials leads to the demand of a precise knowledge of the fatigue behavior and the corresponding failure mechanisms in the very high cycle fatigue (VHCF) range. To realise fatigue investigations for more than 108 loading cycles in an economic reasonable time a novel ultrasonic fatigue testing facility (UTF) for cyclic three-point bending was developed and patented. To avoid critical internal heating due to viscoelastic damping and internal friction, the fatigue testing at 20 kHz is performed in resonance as well as in pulse-pause control resulting in an effective testing frequency of ~1 kHz and the capability of performing 109 loading cycles in less than twelve days. The fatigue behavior of carbon fiber twill 2/2 fabric reinforced polyphenylene sulfide (CF-PPS) and carbon fiber 4-H satin fabric reinforced epoxy resin (CF-EP) was investigated. To study the induced fatigue damage of CF-PPS and CF-EP in the VHCF regime in detail, the fatigue mechanisms and damage development were characterized by light optical and SEM investigations during interruptions of constant amplitude tests (CAT). Lifetime-oriented investigations showed a significant decrease of the bearable stress amplitudes of CF-PPS and CFEP in the range between 106 to 109 loading cycles. The ultrasonically fatigued thermoset matrix composite showed a significantly different VHCF behavior in comparison to the investigated thermoplastic matrix composite: No fiber-matrix debonding or transversal cracks were present on the specimen edges, but a sudden specimen failure along with carbon fiber breakage have been observed. The fatigue shear strength at 109 cycles for CF-PPS could be determined to τa, 13 = 4.2 MPa and to τa, 13 = 15.8 MPa for the thermoset material CF-EP.

ULTRASONIC FATIGUE BEHAVIOR OF A Fe-BASED WARM-COMPACTED POWDER METALLURGY MATERIAL

2013 ◽  
Vol 27 (19) ◽  
pp. 1341027
Author(s):  
YU-HENG LU ◽  
XUAN YE ◽  
LEI HU ◽  
FEI LUO ◽  
ZHI-YU XIAO
Keyword(s):  
Heat Treatment ◽  
Powder Metallurgy ◽  
Fatigue Strength ◽  
Fatigue Test ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Powder Metallurgy Material ◽  
Ultrasonic Fatigue ◽  
Ultrasonic Fatigue Test ◽  
Axial Fatigue

Fe -2 Cu -2 Ni -1 Mo -1 C powder metallurgy material was fabricated by die-wall lubricated warm compaction and ultrasonic fatigue test was carried out for as-sintered and heat treatment samples. Material fatigue strength reaches 249 MPa under axial fatigue testing. The sintered material consists of acicular martensite, pearlite, bainite and retained austenite. Tempered martensite is the major phases after heat-treatment. Cleavage plane and dimples is mixed fracture for sample after axial fatigue test. Mechanical properties of after heat treatment materials are improved and fatigue strength reaches 382 MPa under 107 cycles in bending ultrasonic fatigue test. The fatigue strength increases significantly in high cycles range.

Influence of Texture and Environmental Effects on Fatigue Behavior of Ti-6Al-4V Alloy

2017 ◽  
Vol 754 ◽  
pp. 39-42 ◽  
Author(s):  
Sergio Baragetti ◽  
Nedunchezhian Srinivasan ◽  
Ravi Kumar
Keyword(s):  
Fatigue Strength ◽  
Grain Boundaries ◽  
Environmental Effects ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Aged Condition ◽  
Air Samples ◽  
Secondary Cracks ◽  
Corrosive Environments

Ti-6Al-4V alloy in solutionized and aged condition was subjected to axial fatigue testing in air and corrosive environments respectively. Severity of the methanol damage as evidenced through fractographic studies, corroborates loss in fatigue strength of samples tested in methanol environment in contrast to samples tested in air. Samples subjected to fatigue loading in NaCl environment revealed extensive secondary cracks along alpha grain boundaries.

Ultra-High Cycle Fatigue Behavior of DZ125 Superalloy Used in Turbine Blades

2015 ◽  
Vol 664 ◽  
pp. 96-103
Author(s):  
Yu Li Gu ◽  
Chun Hu Tao
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Turbine Blades ◽  
Frequency Effect ◽  
Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Ultra High Cycle Fatigue ◽  
Fish Eye

The high temperature ultra-high cycle fatigue (UHCF) behaviors of DZ125 superalloy used in aero-engine turbine blades were systematically studied. The results show that the fatigue fracture still occurs above 108 at the frequency of 20kHz, R=-1 and 700°C. There is a negligible frequency effect for the DZ125 superalloy, therefore, it is proposed that the ultrasonic fatigue testing could be expected as an accelerated fatigue testing method. Fatigue cracks originate from the subsurface of the specimens, where have no metallurgy defects or “fish eye” character. The crystal orientation change of the alloy is very little after fatigue.The maximum value changed for the elastic modulus of the alloy is about 30GPa after fatigue compared with that before fatigue.

scholarly journals Very High Cycle Fatigue Behavior of Carbon Manganese Steels

2010 ◽  
Vol 146-147 ◽  
pp. 1780-1783
Author(s):  
Hong Qian Xue ◽  
Danièle Wagner
Keyword(s):  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Effect Of Temperature ◽  
Testing System ◽  
Loading Frequency ◽  
Ultrasonic Fatigue ◽  
Carbon Manganese Steels ◽  
Temperature Scanning ◽  
Initial Results ◽  
Manganese Steels

An ultrasonic fatigue testing system capable of operating at temperatures at 250 has been introduce to study the fatigue behavior of carbon manganese steels (A42 and A48) and loading frequency of approximately 20 kHz. Endurance limit results were comparable to those generated at room temperature to determine the effect of temperature. Scanning electron microscopy was then used to determine the initiation sites and the failure mechanisms. Initial results indicate that fatigue strength decrease a little at 250 , interior inclusions were the major microstructural feature responsible for crack initiation in the alloy.

Sign in / Sign up

Export Citation Format

Share Document