scholarly journals Low-Cycle Fatigue Properties of the X70 High-Frequency Electric-Resistant Welded Pipes

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Peng Tian ◽  
Kai Xu ◽  
Guang-ping Lu ◽  
Gui-ying Qiao ◽  
Fu-ren Xiao
Keyword(s):  
Weld Joint ◽  
High Frequency ◽  
Surface Defects ◽  
Low Cycle Fatigue ◽  
Postweld Heat Treatment ◽  
Fatigue Properties ◽  
Surface Finishing ◽  
Future Research ◽  
Line Pipe ◽  
Microstructural Coarsening

The strength, toughness, corrosion, and fatigue resistance are the main requirements for evaluating the integrity of a pipeline. In this study, the tensile strength, impact toughness, and fatigue properties of the pipe body and weld joint of an X70 high-frequency electric-resistant welded (HFW) pipe were measured and the effects of microstructure and surface defects at weld joint on properties were discussed. Results show the appearance of a weakened zone at the weld joint of the X70 HFW pipe. Nevertheless, all mechanical properties, including strength and impact energy, were superior to the specified values of the API specifications for the X70 line pipe. The reduced strength, toughness, and resistance to S-N fatigue of the weld joint caused the microstructural coarsening at the weld junction zone. However, for the specimens without surface finishing, the resistance to S-N fatigue for the weld joint was further reduced. This phenomenon was mainly attributed to the burring defects and microstructural coarsening at the heat-affected zone (HAZ). Therefore, to improve the quality of the X70 HFW pipe, refining the microstructure of weld joint and reducing the deburring defects by optimizing the postweld heat treatment (PWHT) and deburring processes should be firstly considered in the future research works.

scholarly journals Low Cycle Fatigue Properties of Alloy 617 base Metal and Weld Joint at Room Temperature

2014 ◽  
Vol 3 ◽  
pp. 2201-2206 ◽  
Author(s):  
Seon-Jin Kim ◽  
Pil-Ho Choi ◽  
Rando Tungga Dewa ◽  
Woo-Gon Kim ◽  
Min-Hwan Kim
Keyword(s):  
Base Metal ◽  
Weld Joint ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Alloy 617

Low Cycle Fatigue Properties of 316LN Stainless Steel Welded by GTAW in Nitrogen Added Environment

2007 ◽  
Vol 345-346 ◽  
pp. 275-278
Author(s):  
Dae Whan Kim ◽  
Chang Hee Han ◽  
Woo Seog Ryu
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Yield Strength ◽  
Base Metal ◽  
Weld Joint ◽  
Low Cycle Fatigue ◽  
Ferrite Content ◽  
Fatigue Properties ◽  
316Ln Stainless Steel ◽  
Type 316Ln Stainless Steel

Tensile and fatigue properties were evaluated for base and welded type 316LN stainless steel. Welding methods were GTAW (308L, Ar environment) and GTAWN (316L, Ar + N2 environment). Yield strength of weld joint was higher than that of base metal but elongation of weld joint was lower than that of base metal. UTS of weld joint was slightly lower than that of base metal. Yield strength and elongation with welding method were almost same. Fatigue life of weld joint was lower than that of base metal but fatigue strength of weld joint was higher than that of base metal. Ferrite content was increased with welding. Fatigue life welded by GTAWN was better than that of GTAW at RT and 600°C. This fatigue life behavior was consistent with the behavior of ferrite content.

Effect of Non-Uniform Deformation on Low Cycle Fatigue Properties of Electron Beam Weld Joint of F82H Steel

2015 ◽  
Vol 68 (3) ◽  
pp. 607-611
Author(s):  
S. Nogami ◽  
W. Guan ◽  
M. Fukuda ◽  
H. Tanigawa ◽  
A. Hasegawa
Keyword(s):  
Electron Beam ◽  
Weld Joint ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Electron Beam Weld ◽  
Uniform Deformation

scholarly journals High and low-cycle-fatigue properties of 17–4 PH manufactured via selective laser melting in as-built, machined and hipped conditions

2021 ◽  
Author(s):  
Franco Concli ◽  
Lorenzo Fraccaroli ◽  
Filippo Nalli ◽  
Luca Cortese
Keyword(s):  
Selective Laser Melting ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
The Other ◽  
Fatigue Properties ◽  
Surface Finishing ◽  
Powder Bed Fusion ◽  
Cycle Fatigue ◽  
Laser Melting ◽  
Powder Bed

AbstractIn the last years, additive manufacturing (AM) has turned into an emerging technology and an increasing number of classes of material powders are now available for this manufacturing process. For large-scale adoption, an accurate knowledge of the mechanical behaviour of the resulting materials is fundamental, also considering that reliable data are often lacking and dedicated standards are still missing for these AM alloys. In this regard, the aim of the present work is to characterize both the high-cycle-fatigue (HFC) and the low-cycle-fatigue (LCF) behaviour of AM 17–4 PH stainless steel (SS). To better understand the performance of the selected alloy, four series of cylindrical samples were manufactured. Three series were produced via selective laser melting (SLM), better known as laser-based powder bed fusion of metals technology using an EOS M280 machine. The first series was tested in the as-built condition, the second was machined before testing to obtain a better surface finishing, while the third series was post-processed via hot isostatic pressing (HIP). Finally, a fourth series of samples was produced from the wrought 17–4 PH material counterpart, for comparison. The understanding and assessment of the influence of surface finishing on the fatigue behaviour of AM materials are fundamental, considering that in most applications the AM parts may present reticular or lattice structures, internal cavities or complex geometries, which must be set into operation in the as-built conditions, since a surface finishing postprocess is not convenient or not feasible at all. On the other side, a HIP process is often suggested to reduce the internal porosities and, therefore, to improve the resulting mechanical properties. The high-cycle-fatigue limits were obtained with a short staircase approach according to the Dixon statistical method. The maximum number of cycles (run-out) was set equal to 50,00,000. The part of the Wöhler diagram relative to finite life was also characterized by means of additional tests at higher stress levels. On the other side, the low-cycle tests allowed to tune the Ramberg–Osgood cyclic curves and the Basquin–Coffin–Manson LCF curves. The results obtained for the four different series of specimens permitted to quantify the reduction of the mechanical performance due to the actual limits of the laser-based powder bed fusion technology (surface quality, internal porosity, different solidification) with respect to traditional manufacturing and could be used to improve design safety and reliability, granting structural integrity of actual applications under elastic and elasto-plastic fatigue loads.

Effect of Texture and {10-12} Twin on the Low Cycle Fatigue Properties of Rolled AZ31 Mg Alloy

2013 ◽  
Vol 51 (5) ◽  
pp. 325-332 ◽  
Author(s):  
Sung Hyuk Park ◽  
Seong-Gu Hong ◽  
Chong Soo Lee ◽  
Ha Sik Kim
Keyword(s):  
Low Cycle Fatigue ◽  
Mg Alloy ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Az31 Mg Alloy

Superior Low-Cycle Fatigue Properties of CoCrNi Compared to CoCrFeMnNi

2020 ◽  
Author(s):  
Kaiju Lu ◽  
Ankur Chauhan ◽  
Mario Walter ◽  
Aditya Srinivasan Tirunilai ◽  
Mike Schneider ◽  
...  
Keyword(s):  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue

Random impact FEM simulation of irregularly-shaped media for parametric study of vibratory surface enhancement

2021 ◽  
pp. 095440542199012
Author(s):  
Jing Zhang ◽  
Joselito Yam Alcaraz ◽  
Swee-Hock Yeo ◽  
Arun Prasanth Nagalingam ◽  
Abhay Gopinath
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Parametric Study ◽  
Thermal Loading ◽  
Low Cycle Fatigue ◽  
Fem Simulation ◽  
Surface Finishing ◽  
Aerospace Materials ◽  
Surface Enhancement ◽  
Steel Balls

Aerospace materials experience high levels of mechanical and thermal loading, high/low cycle fatigue, and damage from foreign objects during service, which can lead to premature retirement. Mechanical surface treatments of metallic components, for example, fan blades and blisks, are proven to improve fatigue life, improve wear resistance and avoid stress corrosion by introducing work hardening, compressive residual stresses of sub-surface, and surface finishing. Vibropeening can enhance aerospace materials’ fatigue life involving the kinetic agitation of hardened steel media in a vibratory finishing machine that induces compressive stresses into the component sub-layers while keeping a finished surface. Spherical steel balls are the most widely used shape among steel-based media and have been explored for decades. However, they are not always versatile, which cannot access deep grooves, sharp corners, and intricate profiles. Steel ballcones or satellites, when mixed with round steel balls and other steel media (diagonals, pins, eclipses, cones), works very well in such areas that ball-shaped media are unable to reach. However, a methodology of study the effect of irregularly-shaped media in surface enhancement processes has not been established. This paper proposes a finite element-based model to present a methodology for the parametric study of vibratory surface enhancement with irregularly-shaped media and investigates residual stress profiles within a treated area of an Inconel component. The methodology is discussed in detail, which involves a stochastic simulation of orientation, impact force, and impact location. The contrasting effects of a high aspect ratio, or an edge contact, as opposed to rounded and oblique contacts are demonstrated, with further analysis on the superposition of these effects. Finally, the simulation results are compared with actual residual stress measurements and was found to have a max percent difference of 34% up to 20 [Formula: see text]m below the media surface.

scholarly journals An approach to emerging optical and optoelectronic applications based on NiO micro- and nanostructures

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
María Taeño ◽  
David Maestre ◽  
Ana Cremades
Keyword(s):  
Gas Sensors ◽  
High Frequency ◽  
Future Research ◽  
Electrochromic Devices ◽  
Fuel Cell Electrodes ◽  
Magnetic Devices ◽  
Optical Microresonators ◽  
Optical Limiters ◽  
Recent Developments ◽  
Potential Applicability

Abstract Nickel oxide (NiO) is one of the very few p-type semiconducting oxides, the study of which is gaining increasing attention in recent years due to its potential applicability in many emerging fields of technological research. Actually, a growing number of scientific works focus on NiO-based electrochromic devices, high-frequency spintronics, fuel cell electrodes, supercapacitors, photocatalyst, chemical/gas sensors, or magnetic devices, among others. However, less has been done so far in the development of NiO-based optical devices, a field in which this versatile transition metal oxide still lags in performance despite its potential applicability. This review could contribute with novelty and new forefront insights on NiO micro and nanostructures with promising applicability in optical and optoelectronic devices. As some examples, NiO lighting devices, optical microresonators, waveguides, optical limiters, and neuromorphic applications are reviewed and analyzed in this work. These emerging functionalities, together with some other recent developments based on NiO micro and nanostructures, can open a new field of research based on this p-type material which still remains scarcely explored from an optical perspective, and would pave the way to future research and scientific advances.

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