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.

scholarly journals Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Heat Treatments ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Before And After ◽  
The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

Residual Stresses in Intrinsic UD-CFRP-Steel-Laminates - Experimental Determination, Identification of Sources, Effects and Modification Approaches

2015 ◽  
Vol 825-826 ◽  
pp. 369-376 ◽  
Author(s):  
Robert Prussak ◽  
Daniel Stefaniak ◽  
Christian Hühne ◽  
Michael Sinapius
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Tensile Strength ◽  
Epoxy Composite ◽  
Thermal Residual Stress ◽  
Fiber Metal Laminates ◽  
Fiber Metal ◽  
Impact Energies ◽  
The Impact ◽  
Specific Impact

This paper focuses on the reduction of process-related thermal residual stress in fiber metal laminates and its impact on the mechanical properties. Different modifications during fabrication of co-cure bonded steel/carbon epoxy composite hybrid structures were investigated. Specific examinations are conducted on UD-CFRP-Steel specimens, modifying temperature, pressure or using a thermal expansion clamp during manufacturing. The impact of these parameters is then measured on the deflection of asymmetrical specimens or due yield-strength measurements of symmetrical specimens. The tensile strength is recorded to investigate the effect of thermal residual stress on the mechanical properties. Impact tests are performed to determine the influence on resulting damage areas at specific impact energies. The experiments revealed that the investigated modifications during processing of UD-CFRP-Steel specimens can significantly lower the thermal residual stress and thereby improve the tensile strength.

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 The degradation of mechanical properties in halloysite nanoclay–polyester nanocomposites exposed to diluted methanol

2016 ◽  
Vol 51 (11) ◽  
pp. 1653-1664 ◽  
Author(s):  
Mohd Shahneel Saharudin ◽  
Rasheed Atif ◽  
Islam Shyha ◽  
Fawad Inam
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Degradation Of Mechanical Properties ◽  
Before And After ◽  
The Matrix ◽  
Methanol Exposure ◽  
The Impact ◽  
And Storage ◽  
Methanol System ◽  
Methanol Absorption

The degradation of mechanical properties in halloysite nanoclay–polyester nanocomposites was studied after an exposure of 24 h in diluted methanol system by clamping test specimens across steel templates. The glass transition temperature ( Tg) and storage modulus increased steadily with the increase of halloysite nanoclays before and after diluted methanol exposure. The addition of nano-fillers was found to reduce liquid uptake by 0.6% in case of 1 wt% reinforcement compared to monolithic polyester. The mechanical properties of polyester-based nanocomposites were found to decrease as a result of diluted methanol absorption. After diluted methanol exposure, the maximum microhardness, tensile, flexural and impact toughness values were observed at 1 wt% of halloysite nanoclay. The microhardness increased from 203 to 294 HV (45% increase). The Young’s modulus increased from 0.49 to 0.83 GPa (70% increase) and the tensile strength increased from 23 to 27 MPa (17.4% increase). The impact toughness increased from 0.19 to 0.54 kJ/m2 in diluted methanol system (184% increase). Surprisingly, the fracture toughness of all types of nanocomposites was found to increase after exposing to diluted methanol due to plasticization effect. Scanning electron microscope images of the fractured surfaces of tensile specimens revealed that the methanol increased the ductility of the matrix and reduced the mechanical properties of the nanocomposites.

In situ investigation of the impact of cyclic thermal variations impact on the mechanical properties of sandy soil.

2020 ◽  
Author(s):  
Sandrine Rosin-Paumier ◽  
Hossein Eslami ◽  
Farimah Masrouri
Keyword(s):  
Mechanical Properties ◽  
Sandy Soil ◽  
In Situ Investigation ◽  
Energy Piles ◽  
Before And After ◽  
Cyclic Variations ◽  
Loading Tests ◽  
Adjacent Soil ◽  
Comparison Of The Results ◽  
The Impact

<p>The incorporation of heat exchangers into geostructures leads to changes in the temperature of the adjacent soil, which may affect its hydro-mechanical properties. In this study, mini-pressiometer tests were carried out in the vicinity of three experimental energy piles of 12 meters length and 0.52-meter diameter installed in saturated sandy soil. Tests were carried out in three locations and in two different depths (namely 3 and 4 meters in depth) before and after cyclic variations of their temperature. The pressuremeter parameters are the pressuremeter modulus EM, the limit pressure PL and the creep-pressure Pf. These parameters characterize the properties of the soils; some measurements were done close to the energy piles (1.25 meters from the center of the pile) using a mini-pressuremeter cell (380 mm in height and 28 mm in diameter). The comparison of the results before and after the four warming-cooling cycles (8° to 19° C) showed a thin thickening of the material at 3 meters depth. These results are coherent with in-lab measurements and with the results of the pile loading tests carried out later on the same site.</p>

Influence of Vanadium on Microstructures and Mechanical Properties of High Strength Normalized Steel

2012 ◽  
Vol 535-537 ◽  
pp. 628-632 ◽  
Author(s):  
Ming Wei Tong ◽  
Ze Xi Yuan ◽  
Kai Guang Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
High Strength ◽  
Polygonal Ferrite ◽  
Strength Index ◽  
The Matrix ◽  
Low Temperature Toughness ◽  
Impact Energies ◽  
The Impact ◽  
Ferrite Grain Size

Considering the specialities of high strength normalized steel, the main roles of vanadium in normalized steel were investigated. The results show that adding vanadium can improve the strength and deteriorate the impact energy, but for vanadium steel, the strengths increase and the impact energies have no changing regulation with increasing vanadium. The microstructures of experimental steels are composed of polygonal ferrite and pearlite, vanadium can not refine ferrite grain size, most of them dissolve into the matrix, and the forms of precipitation in vanadium steel are complex carbonitrides. Grain refinement plays a greater role in improving the low temperature toughness of high strength normalized steels, the strength index is firstly considered in designing this kind of steels.

Research on the Morphology and Mechanical Properties of 304 Stainless Steels of Intergranular Corrosion

2012 ◽  
Vol 251 ◽  
pp. 421-425
Author(s):  
Guo Sheng Cai ◽  
Du Xiong Wang ◽  
Rong Fa Chen ◽  
Long Wu ◽  
Yi Pan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Intergranular Corrosion ◽  
Surface Corrosion ◽  
Bending Force ◽  
Micro Cracks ◽  
Before And After ◽  
Metallurgical Structure ◽  
Morphology And Mechanical Properties

In the paper, the steel intergranular corrosion of 304 stainless steels was studied in detail with the method of copper sulfate. The macro morphology, mechanical property and metallurgical structure were also discussed by contrast of before and after corrosion. The results indicated that many trans-crystalline cracks and micro cracks were found on the surface of stainless steel. The max bending force was decreased from 7.225KN to 4.926KN; the deposited carbide was seen on corroded grain boundary with the dropping of grain. The conclusions are important to analysis of surface corrosion of stainless steel.

scholarly journals Process Design Strategies for Producing Heavy Section Steel with Improved Quality

2013 ◽  
Vol 652-654 ◽  
pp. 988-991
Author(s):  
Jing Wei Zhao ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei ◽  
Chong Soo Lee
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Longitudinal Direction ◽  
Ring Rolling ◽  
Design Strategies ◽  
Noticeable Effect ◽  
Heavy Section ◽  
Microstructure And Mechanical Properties ◽  
Impact Energies ◽  
The Impact

Uniformity of microstructure and mechanical properties is required for the heavy section steel. In the present work, a heavy section wind tower flange was manufactured by controlled ring-rolling. Post-rolling heat treatment was employed to optimize the microstructure and mechanical properties. The chemical composition, microstructure and mechanical properties in different zones of the flange were investigated. The results showed that the chemical composition and microstructure were uniformly distributed in the flange. The tensile strength showed similar values in different sampling locations. The strain and impact energies of specimens prepared along the longitudinal direction were higher than that prepared along both the radius and thickness directions. Notch direction did not have noticeable effect on the impact energy. It is demonstrated that the designed process is effective for producing heavy section steel with improved quality.

Sign in / Sign up

Export Citation Format

Share Document