A Study on Precipitation in Clean Micro Alloyed Steels

2001 ◽  
Vol 7 (S2) ◽  
pp. 1264-1265
Author(s):  
Yuanli Wang ◽  
Delu Liu ◽  
Jie Fu ◽  
Jian Zhu

Much attention has been devoted to develop the new generation of microalloyed steels in recent years to meet the needs of high performance and low cost for the 21st century. The new type of steels is characterized by reduced carbon content, improved cleanness and refined grain size through the phase transformations.11'21 Precipitation of the carbonitrides in the steels is also one of the keypoints for controlling mechanical properties of the steels.In the present work ultra-low carbon clean microalloyed steels, which contain 0.029∽0.047(wt)%C, 1.48∽1.54(wt)% Mn, 0.044∽0.052(wt)%Nb, 0.025∽0.044Ti(wt)%, 0.0015∽0.0020(wt)%B and 0.0045∽0.0070(wt)%N, were prepared in a vacuum induction furnace in laboratory. The contents of S and P of the steels are 0.0005(wt)% and 0.0010∽0.0024(wt)% respectively. Total amount of the impurity elements O, S, P and H in the steels is 0.0061∽0.0077%. Dominant component of the structure in both casting and as-forged samples is acicular ferrite or bainite.

2020 ◽  
Vol 4 (10) ◽  
pp. 5313-5326 ◽  
Author(s):  
S. Rajkumar ◽  
E. Elanthamilan ◽  
J. Princy Merlin ◽  
I. Jenisha Daisy Priscillal ◽  
I. Sharmila Lydia

The as-synthesized CuCo2O4/PANI nanocomposite has emerged as a new type of electrode material for energy storage applications due to its low cost and sustainable and high electrochemical performance.


Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1448 ◽  
Author(s):  
Alberto Benato ◽  
Anna Stoppato

Renewable energy sources are the most useful way to generate clean energy and guide the transition toward green power generation and a low-carbon economy. Among renewables, the best alternative to electricity generation from fossil fuels is solar energy because it is the most abundant and does not release pollutants during conversion processes. Despite the photovoltaic (PV) module ability to produce electricity in an eco-friendly way, PV cells are extremely sensitive to temperature increments. This can result in efficiency drop of 0.25%/ ∘ C to 0.5%/ ∘ C. To overcome this issue, manufacturers and researchers are devoted to the improvement of PV cell efficiency by decreasing operating temperature. For this purpose, the authors have developed a low-cost and high-performance PV cooling system that can drastically reduce module operating temperature. In the present work, the authors present a set of experimental measurements devoted to selecting the PV cooling arrangement that guarantees the best compromise of water-film uniformity, module temperature reduction, water-consumption minimization, and module power production maximization. Results show that a cooling system equipped with 3 nozzles characterized by a spraying angle of 90 ∘ , working with an inlet pressure of 1.5 bar, and which remains active for 30 s and is switched off for 120 s, can reduce module temperature by 28 ∘ C and improve the module efficiency by about 14%. In addition, cost per single module of the cooling system is only 15 €.


2015 ◽  
Vol 229 ◽  
pp. 125-130
Author(s):  
Agnieszka Szkliniarz ◽  
Wojciech Szkliniarz

The paper characterized the phase composition, microstructure and selected mechanical properties at room temperature and at temperature corresponding to the expected operating conditions of a new generation of TiAl based alloys melted in a vacuum induction furnace in a special graphite crucibles.


Author(s):  
Shimeng Zhao ◽  
Jialin Li ◽  
Haixia Chen ◽  
Jianxin Zhang

Abstract Rechargeable aluminum ion batteries (AIBs) have attracted much attention because of their high charge density, low cost, and low flammability. Transition metal sulfides are a class of cathode materials that have been extensively studied. In this report, Bi2S3 nanorods and Bi2S3/MoS2 nanorods were synthesized by the hydrothermal method as new type of cathode materials for rechargeable AIBs. The diameter of Bi2S3/MoS2 nanorods is 20–100 nm. The Bi2S3 nanorods display high initial charge and discharge capacities of 343.3 and 251 mA h/g with a current density of 1 A/g. The static cycling for the Bi2S3/MoS2 nanorods electrode at 1 A/g denotes high stability with a specific capacity of 132.9 mA h/g after 100 cycles. The charging voltage platform of Bi2S3 nanorods and Bi2S3/MoS2 nanorods is at 1.1–1.4 V, and the discharge voltage platform is at around 0.8 V. The well-defined heterojunction maintains the stability of the Bi2S3 structure during long-term cycling, which is desirable for aluminum ion batteries. This strategy reveals new insights for designing cathode materials of high-performance AIBs.


Nanophotonics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 2347-2358 ◽  
Author(s):  
Jun Zhou ◽  
Ruoshan Lei ◽  
Huanping Wang ◽  
Youjie Hua ◽  
Denghao Li ◽  
...  

AbstractFor achieving well-performing optical thermometry, a new type of dual-mode optical thermometer is explored based on the valley-to-peak ratio (VPR) and fluorescence lifetime of Eu3+ emissions in the ZrO2:Eu3+ nanocrystals with sizes down to 10 nm. In the VPR strategy, the intensity ratio between the valley (600 nm) generated by the emission band overlap and the 606 nm peak (5D0→7F2), which is highly temperature sensitive, is employed, giving the maximum relative sensing sensitivity (Sr) of 1.8% K−1 at 293 K and good anti-interference performance. Meanwhile, the 606 nm emission exhibits a temperature-dependent decay lifetime with the highest Sr of 0.33% K−1 at 573 K, which is due to the promoted nonradiative relaxation with temperature. These results provide useful information for constructing high-performance dual-mode optical thermometers, which may further stimulate the development of photosensitive nanomaterials for frontier applications.


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Yasong Li ◽  
Ruixuan Li ◽  
Yong Zhang

A series of as-cast lightweight multicomponent alloys Al(86-x)Mg10Zn2 Cu2 Six (x=0, 0.3, 0.6, 0.9, 1.2 at.%) were prepared by a vacuum induction furnace with a steel die. With the addition of Si, the reticular white Al-Cu phase deposited were gradually replaced by the gray eutectic Mg-Si phase, while the compressive strength of the alloys increases first and then decreases slowly. It is particularly noteworthy that the compression plasticity also exhibits this trend. When the Si content is 0.9 at.%, the compressive strength reaches its maximum at 779.11 MPa and the compressive plasticity reaches 20.91%. The effect of the addition of Si on the serration behavior of alloy was also studied; we found that the addition of Si introduces a new MgSi phase, and with the change of Si is significantly affects the morphology of the precipitated phase, which affects the serration behavior of the alloys. The comprehensive mechanical properties of the alloy are optimal at the critical point where the serration behavior disappears.In this work, we have provided a method and a composition for the preparation of a low-cost, high-strength, lightweight medium-entropy alloys.


Metallurgist ◽  
2015 ◽  
Vol 58 (9-10) ◽  
pp. 909-915 ◽  
Author(s):  
A. I. Zaitsev ◽  
I. G. Rodionova ◽  
A. A. Pavlov ◽  
O. N. Baklanova ◽  
I. V. Lyasotskii

2012 ◽  
Vol 22 (12) ◽  
pp. 5560 ◽  
Author(s):  
Keyu Xie ◽  
Zhouguang Lu ◽  
Haitao Huang ◽  
Wei Lu ◽  
Yanqing Lai ◽  
...  

2017 ◽  
Vol 36 (2) ◽  
pp. 145-153 ◽  
Author(s):  
M. Z. Jiang ◽  
Y. C. Yu ◽  
H. Li ◽  
X. Ren ◽  
S. B. Wang

AbstractLow carbon high manganese steels with different Ce contents were melted in medium frequency vacuum induction furnace. The microstructures and mechanical properties of steels were studied by OM, SEM, EDS and mechanical property testing. The results showed that the microstructures of experimental steels were refined remarkably, inclusions distributed more finely and uniformly, the tensile strength and impact toughness of tested steels both improved greatly after the addition of Ce. Thermodynamic calculation results demonstrated that Ce contained inclusions were Ce2O3 and Ce3S4, which agreed well with the results observed by SEM and EDS. By analysis of two-dimensional lattice disregistry, it was shown that the lattice misfit parameter between δ-Fe and Ce2O3, Ce3S4 are less than 6 %, which indicated that Ce2O3 and Ce3S4 could effectively act as the heterogeneous nuclei of initial δ-Fe. Therefore, the microstructures were refined significantly and the mechanical properties were improved correspondingly in Ce-added low carbon high manganese steels.


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