The Impact Of Thermal Aging On The Electrical Endurance Of Corona-Resistant Magnet Wires

2020 ◽  
Author(s):  
T. Han ◽  
A. Caprara ◽  
G. Ciotti ◽  
A. Rumi ◽  
A. Cavallini
Keyword(s):  
Thermal Aging ◽  
The Impact

scholarly journals Influence of Mo Additions on the Mechanical Properties of Cast Duplex Stainless Steels before and after Thermal Aging

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 295
Author(s):  
Shilei Li ◽  
Yanli Wang ◽  
Xitao Wang
Keyword(s):  
Mechanical Properties ◽  
Stainless Steels ◽  
Thermal Aging ◽  
Decomposition Kinetics ◽  
Before And After ◽  
Mo Content ◽  
Impact Energies ◽  
The Impact ◽  
Hardness Values ◽  
Mo Additions

The influence of Mo additions on the mechanical properties of cast duplex stainless steel (CDSS) before and after thermal aging was investigated using a series of model alloys with different Mo contents ranging from 0 to 1.75 wt%. By increasing Mo content, the content, morphology, and distribution of ferrite in CDSS change significantly. After thermal aging at 400 °C for 3000 h, the impact properties of all CDSS specimens obviously decline, and their hardness values in ferrite significantly increase. The impact energies of the aged CDSS decline, and the proportion of cleavage features significantly increases with Mo content increasing. The spinodal decomposition kinetics in ferrite is not significantly affected by the Mo contents. High content and interconnected ferrite will lead to the severe embrittlement in CDSS after thermal aging.

Thermal Ageing Embrittlement of Casting Duplex Stainless Steels for Nuclear Power Plant

2010 ◽  
Author(s):  
Yuhong Yao ◽  
Jianfeng Wei ◽  
Jiangnan Liu ◽  
Zhengpin Wang ◽  
Yu Wang
Keyword(s):  
Stainless Steels ◽  
Thermal Aging ◽  
Nuclear Power ◽  
Power Plants ◽  
Ageing Time ◽  
Thermal Ageing ◽  
Duplex Stainless Steels ◽  
Impact Properties ◽  
Α Phase ◽  
The Impact

Cast duplex stainless steels (CSS) used for PWR pipes are degraded due to thermal ageing embrittlement during long-term service at 288 °C to 327 °C. Z3CN20-09M Cast duplex Stainless Steels (CSS) made in France for domestic nuclear power plants were thermally aged at 400 °C for 100 h, 300 h, 1000 h, 3000 h and 10000 h. The tensile properties and the impact properties at different thermal aging duration were measured and the effects of the thermal aging time on the microscopic structures and substructures of Z3CN20-09M were respectively investigated by optical microscopy and transmission electron microscopy. The results showed that the tensile strengths of Z3CN20-09M CSS increased gradually with the increment of the thermal ageing time, whereas the impact properties decreased with the prolonging of the thermal ageing time. After long thermal ageing time the dislocation configurations were greatly changed in austenite, and there were precipitates along the austenite-ferrite interface. Moreover, the iron-rich α phase and the chromium-rich α phase precipitated in ferrite aged for 10000h by nucleation and growth rather than the spinodal decomposition. All of above revealed that Z3CN20-09M CSS became brittle during thermal ageing.

scholarly journals Non-hardening embrittlement mechanism of pressure vessel steel Ni-Cr-Mo-V welds during thermal aging

2020 ◽  
Vol 12 (2) ◽  
pp. 168781402090456
Author(s):  
Guojun Wei ◽  
Chenglong Wang ◽  
Xingwang Yang ◽  
Zhenfeng Tong ◽  
Wenwang Wu
Keyword(s):  
Weld Metal ◽  
Thermal Aging ◽  
Pressure Vessel ◽  
Impact Test ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Reactor Pressure Vessel ◽  
Impact Fracture ◽  
The Impact ◽  
Reactor Pressure

The mechanical performance of reactor pressure vessel materials is an important factor in the safety and economics of the operation of a nuclear power plant. The ductile-to-brittle transition temperature tested by Charpy impact test is the key parameter for evaluating the reactor pressure vessel embrittlement. In this article, the study of thermal aging embrittlement of temperature sets of reactor pressure vessel surveillance Ni-Cr-Mo-V steel weld metal was conducted by Charpy impact test. The thermal aging effect on the impact fracture behavior was analyzed. The impact test of the three batches of weld surveillance sample indicated that the weld metal embrittled during thermal aging. The study of impact fracture and Auger electron spectroscopy indicated that the element P segregated to the grain boundaries and lowered their cohesion strength during the long-term thermal aging. Therefore, the non-hardening embrittlement of Ni-Cr-Mo-V steel welds in a reactor pressure vessel caused by segregation of impurity elements P occurs during thermal aging.

Effect of Thermal Aging on Microstructural Evolution in Ferrite of Duplex Stainless Steel in Nuclear Power Plant Applications

2017 ◽  
Vol 898 ◽  
pp. 818-825
Author(s):  
B. Zhang ◽  
F. Xue ◽  
S.L. Li ◽  
Xi Tao Wang ◽  
N.N. Liang ◽  
...  
Keyword(s):  
Aging Time ◽  
Thermal Aging ◽  
Atom Probe Tomography ◽  
Nuclear Power ◽  
Impact Test ◽  
Atom Probe ◽  
Nanoindentation Test ◽  
Α Phase ◽  
The Impact ◽  
Duplex Steels

Z3CN20-09M duplex steels are thermally aged at 400oC for up to 20,000 h. The mechanical properties have been characterized by Charpy V-notch impact test and nanoindentation test. It is found that the nanohardness in ferrite increases and the impact toughness decreases with aging time. Moreover, the distribution of alloying elements has been carefully characterized using atom probe tomography (APT). The results indicate that the ferrite decomposes into Cr-rich α' and Cr-lean α phase during the thermal aging and Ni-rich G-phase forms in ferrite. The effect of aging time on solute nanostructure has been investigated systematically.

Thermal Aging Embrittlement Evaluation of Nuclear Primary Pipe Steel by Ductile to Brittle Transition Test

2010 ◽  
Vol 97-101 ◽  
pp. 797-800 ◽  
Author(s):  
Fei Xue ◽  
Wei Wei Yu ◽  
Zhao Xi Wang ◽  
Guo Gang Shu ◽  
Xi Tao Wang ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Pipe Steel ◽  
Pipe Material ◽  
Brittle Transition ◽  
Impact Tests ◽  
Different Temperatures ◽  
Ductile To Brittle Transition ◽  
And Shifts ◽  
The Impact ◽  
Transition Curves

In order to determine the ductile to brittle transition behavior of nuclear primary pipe material (Z3CN20.09M) during the thermal aging procedure, instrumented impact tests at different temperatures were performed on Z3CN20.09M aged at 400°C for up to 3000 hours. The load-deflection curves from the instrumented impact tests described both the loading and the fracture stages, from which the dynamic strengths and energy were calculated. The results indicated that the thermal aging decreases the impact energy and shifts the ductile-to-brittle transition curves to higher temperatures.

Analysis of the Mechanical Properties of Pristine and Thermally Aged PC/PMMA Micro and Nanolayered Films

2010 ◽  
Author(s):  
Hui Shen ◽  
N. D. Gannon
Keyword(s):  
Mechanical Properties ◽  
Film Thickness ◽  
Polymer Films ◽  
Thermal Aging ◽  
Layered Structures ◽  
Mechanical Tests ◽  
Hierarchical Systems ◽  
Process Technology ◽  
Barrier Materials ◽  
The Impact

Microlayered polymer films are synthetic polymers with biomimicking layered structures which have been successfully commercialized. Nanolayered polymer films have been developed in recent years using advanced process technology. The innovative nanolayered polymer films have more complex hierarchical systems with truly biomimic nature. There are many potential applications for the nanolayered films such as gas barrier materials and spherical gradient refractive index lens. However, as polymers possess many properties that are different from metals and other traditional materials, the mechanical properties of the polymer films can vary widely depending on the material formulation, environmental temperature, and time. In this work, standard mechanical tests have been conducted to study the relationship between the mechanical properties and the layered structures. The impact of thermal aging on the mechanical behavior of the micro and nanolayered polymer films has also been investigated experimentally. The composition of the polymer films under study are 50vol% polycarbonate (PC) and 50vol% poly(methyl methacrylate) (PMMA). The layer thickness ranges from 31 nm to 32 μm and the film thickness 50.8 μm to 254 μm. These films were thermally aged at 115°C and 125°C in a constant temperature oven for up to four weeks. The mechanical properties, including the modulus of elasticity, tensile strength and ductility, have been tested on the pristine and thermally aged films. It has been observed that the mechanical properties of the films vary with the layered structure and film thickness. The thermal aging temperature and aging time have significant effects on the overall character of the stress-strain responses. Films with different thicknesses and layer formations respond to the thermal conditions differently.

Thermal aging of electrolytes used in lithium-ion batteries – An investigation of the impact of protic impurities and different housing materials

2014 ◽  
Vol 267 ◽  
pp. 255-259 ◽  
Author(s):  
Patricia Handel ◽  
Gisela Fauler ◽  
Katja Kapper ◽  
Martin Schmuck ◽  
Christoph Stangl ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Thermal Aging ◽  
Lithium Ion ◽  
Housing Materials ◽  
The Impact

scholarly journals Dielectric Measurement Based Deducted Quantities to Track Repetitive, Short-Term Thermal Aging of Polyvinyl Chloride (PVC) Cable Insulation

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2809
Author(s):  
Gergely Márk Csányi ◽  
Semih Bal ◽  
Zoltán Ádám Tamus
Keyword(s):  
Thermal Aging ◽  
Weight Percent ◽  
Dioctyl Phthalate ◽  
Dielectric Measurement ◽  
Voltage Response ◽  
Short Term ◽  
Response Measurement ◽  
Phthalate Plasticizer ◽  
Different Temperatures ◽  
The Impact

The effect of short-term (3- and 6-h-long) periodic thermal aging was investigated at three different temperatures on PVC cables and PVC films. Three different temperatures (110, 125, and 140 °C) were used for aging PVC cables and one (110 °C) for PVC films. PVC films were prepared for the investigation containing 0, 30, 40, and 50 weight percent of dioctyl phthalate plasticizer (DOP). The effect of short-term thermal aging was monitored by electrical (dielectric spectrum and voltage response measurement) and mechanical (Shore D hardness) methods. From the loss factor measurements, different deducted quantities were calculated and compared with Shore D hardness, which has been shown to be a parameter reflecting the effect of short-term thermal aging on PVC insulation. The measurements revealed that Shore D hardness is not the best property for monitoring aging. Instead, increasing dissipated power and the shifting behavior of tan δ–frequency curves proved to be the best phenomena for assessing the impact of thermal aging. Simple deducted quantities may provide a basis for following short-term thermal aging.

Impact of Thermal Aging on the Growth of Cu-Sn Intermetallic Compounds in Pb-Free Solder Joints in 2512 Resistors

2009 ◽  
Author(s):  
Preeti Chauhan ◽  
Michael Osterman ◽  
Michael Pecht
Keyword(s):  
Intermetallic Compounds ◽  
Thermal Aging ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Solder Joints ◽  
Material Behavior ◽  
Sac305 Solder ◽  
Interfacial Imcs ◽  
Aging Conditions ◽  
The Impact

Interfacial intermetallic compounds (IMCs) in solder joints are formed during soldering and continue to grow after assembly. Excessive interfacial IMC growth may impact the reliability of solder interconnections due to changes in material behavior. The impact of thermal aging on IMC growth can be determined by subjecting assemblies to elevated temperatures and determining the interfacial IMC growth. This paper discusses the interfacial IMCs formed in the solder-Cu interface for SAC305, SAC105, and Sn-0.7Cu-0.05Ni+Ge (SN100C) assemblies. Test assemblies were produced using tin-finished 2512 resistors soldered onto OSP-finished copper lands. The assemblies were subjected to aging conditions of 100°C for 24 h and 600 h; and 150°C for 24 h and the impact of high temperature aging on the thickness of IMCs formed at solder-Cu interface was studied. Samples stored at room temperature for 600 h were the reference specimen for the experiment. The IMC growth observed in the lead-free solders was compared with that in eutectic SnPb. Interfacial IMCs formed in room temperature conditioned specimens were scallop shaped and non-uniform. The IMC structure evolved with aging temperature and duration resulting in smoother and more uniform IMCs in 100°C/600 h aged samples. A comparison of IMC thickness in the solders at given aging conditions revealed that SAC305 exhibited highest IMC thickness, followed by SAC105 and SN100C. SnPb showed the least IMC thickness at all aging conditions except at 150°C for 24 h. At this condition, SnPb showed IMC thickness comparable to SAC305 solder and was higher than other solders.

scholarly journals Thermal aging behavior characteristics of asphalt binder modified by nano-stabilizer based on DSR and AFM

2021 ◽  
Vol 10 (1) ◽  
pp. 1157-1182
Author(s):  
Xiaolong Sun ◽  
Junshen Yuan ◽  
Yikang Zhang ◽  
Yingmei Yin ◽  
Jianbing Lv ◽  
...  
Keyword(s):  
Aging Time ◽  
Thermal Aging ◽  
Asphalt Binder ◽  
Creep Recovery ◽  
Modified Asphalt ◽  
Atomic Force ◽  
Modified Asphalt Binder ◽  
Typical Morphology ◽  
Behavior Characteristics ◽  
The Impact

Abstract In order to clarify the effect of thermal aging on the nano-stabilized modified asphalt binder, TINUVIN 770 (T770) hindered amine light stabilizer of nanoscale was selected as aging modifying agent to prepare modified asphalt. The impact of thermal aging on the rheological properties of T770-modified asphalt was investigated using dynamic shear rheological test of frequency sweep and multiple stress creep recovery test. The surface roughness variation of T770-modified asphalt was characterized by using atomic force microscope throughout the thermal aging process. Furthermore, the typical morphology and parameter features of T770-modified asphalt were identified. The results showed that with the extension of thermal aging time, the high temperature rutting resistance of T770-modified asphalt was improved, while the unrecoverable creep compliance was degraded. When the thermal aging time exceeded 6 h, the bee structure appeared on the surface of T770-modified asphalt. Meanwhile, with the increase in thermal aging time, the special structure formed on the surface of asphalt gradually became smaller. The surface fluctuation difference of T770-modified asphalt reflected the better thermal aging resistance property of T770-modified asphalt than 70# asphalt.

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