scholarly journals Effect of Aluminum Addition with Nitrogen on K-Carbide Formation in Carbon-Mn Steel

2021 ◽  
Author(s):  
Shahid Hussain ABRO ◽  
Alidad CHANDIO ◽  
Asif Ahmed SHAIKH ◽  
Norbaizura NORDIN ◽  
Hamza SUHARWARDI
Keyword(s):  
Research Work ◽  
Melting Furnace ◽  
Chemical Effect ◽  
Small Samples ◽  
Carbide Formation ◽  
Induction Melting ◽  
Steel Matrix ◽  
Tem Analysis ◽  
Aluminum Addition ◽  
Heat Treated

An attempt has been made in the present research work to investigate the role and influence of chemical effect of aluminum addition in the experimental steel towards the formation of k-carbides. Two steel grades were made with and without aluminum addition by induction melting furnace and were cast to ingots. Steel A has no aluminum addition and steel B has some aluminum content. These ingots were then solution heat treated on a temperature of 1200°C for 2-hours’ time and were cooled in the air. After that, they were hot rolled to drawn in plate and sheet. The small samples were cut from bulk and were then heat-treated at 800°C for 1 hour and quenched. Microstructure by OM and SEM was captured. In steel A there was no k-carbide present in the matrix and surprisingly in steel B, small fine k-carbides were present this was then confirmed by XRD later. OM, SEM, and TEM analysis revealed that the presence of k-carbides in steel B makes less dense. It was concluded that aluminum in conjunction with nitrogen forms the small nitride particles having a high melting point does not dissolve during the melting and casting such particles are known as AlN or aluminum nitride particles was observed by TEM along with EDS was the main reason to support the formation of k-carbides, these fine nano level k-carbides are orderly distributed in the steel matrix as was shown by XRD peaks.

Synthesis and Purification of Silicon Carbide Powders for Crystal Growth

2012 ◽  
Vol 717-720 ◽  
pp. 37-40 ◽  
Author(s):  
Ta Ching Hsiao ◽  
Sheng Tsao
Keyword(s):  
Silicon Carbide ◽  
Crystal Growth ◽  
Acid Leaching ◽  
Melting Furnace ◽  
Impurity Content ◽  
Low Pressure ◽  
Free Carbon ◽  
Vacuum Induction Melting ◽  
Carbide Formation ◽  
Induction Melting

Silicon carbide powders were prepared in a vacuum induction melting furnace (VIM). Silica and silicon were used as sources of silicon, and graphite powder was used a source of carbon. Pressures of 0.1 and 0.01 atm were selected as the operation conditions, and different silicon carbide powders were prepared. Free carbon and remnant silica were removed by high-temperature baking in air and acid leaching. Low-pressure powders show better crystallinity; moreover, free carbon and silica were rarely found in the product after baking and leaching. The low-pressure grains were prismatic whereas the high-pressure grains were porous. This shows that pressure is a critical parameter in silicon carbide formation, and low-pressure makes the low-temperature synthesis of silicon carbide feasible. Glow discharge mass spectra were used to analyze the impurity content in silicon carbide powders. After baking and leaching, the purity is increased from 3N5 (99.95 wt.%) to 4N5 (99.995 wt.%). Further purification procedures will be combined to meet the quality requirements for crystal growth.

scholarly journals Evaluation of Strength and Microstructural Properties of Heat Treated High-Molybdenum Content Maraging Steel

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1446
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman
Keyword(s):  
Optimum Condition ◽  
Tensile Properties ◽  
Maraging Steel ◽  
Melting Furnace ◽  
Steel Sample ◽  
Molybdenum Content ◽  
Raw Material ◽  
Induction Melting ◽  
Microstructural Properties ◽  
Heat Treated

Effect of high molybdenum content ~10% as an alloying element on the strength and microstructural properties of 11% nickel—1.25% titanium maraging steel was evaluated. To increase the homogeneity and cleanliness of produced ingot, the investigated steel sample was produced by melting the raw material in an open-air induction melting furnace followed by refining utilizing a direct current electro-slag refining machine. The produced steel samples were both forged and heat-treated in optimum condition to acquire the full capacity of mechanical properties especially the tensile properties. After Forging and heat treatment at optimum condition, steel samples were evaluated by optical microscopy (OM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) analysis, electron backscattering diffraction (EBSD), and transmission electron microscopy (TEM). The experimental data showed that this steel sample has ultimate strength ~2100 MPa and elongation around 14%. High tensile properties obtained may be attributed on one hand due to the presence of high alloying lamellar martensite phase and lamellar austenite phase which has high dislocation intensity, and on the other hand, due to the high homogeneity and cleanliness of investigated samples from large nonmetallic inclusions. The results also show that a high amount of intermetallic compounds (NiMo3 and NiTi3) which are completely round and have a very low size not more than hundred nanometers.

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

Nanozirconium Carbide Powder Synthesis via Carbothermal Route

2013 ◽  
Vol 334-335 ◽  
pp. 381-386 ◽  
Author(s):  
F. Arianpour ◽  
F. Kazemi ◽  
Hamid Reza Rezaie ◽  
A. Asjodi ◽  
J. Liu
Keyword(s):  
Carbon Sources ◽  
Zirconium Carbide ◽  
Carbide Powder ◽  
Carbide Formation ◽  
Matrix Composites ◽  
Powder Synthesis ◽  
High Refractoriness ◽  
Heat Treated ◽  
Crystallite Sizes ◽  
20 Nm

Zirconium carbide (ZrC) has extended application in many ceramic and metal matrix composites especially used for ultra high temperature conditions. The synthesis of zirconium carbide powder is costly and difficult because of its high refractoriness and chemically inert properties. In this research, the synthesis of zirconium carbide nanopowder at low temperature via carbothermal reduction route was investigated according to thermodynamic data. The starting materials were zirconium acetate and sucrose as zirconium and carbon sources, respectively. After preparation of different carbon/zirconium ratio containing precursors, the dried precursors were heat treated at 1400°C and vacuum atmosphere. Also the ZrC formation was followed by thermal analysis of the produced precursors. The phase evolutions and microstructural studies were carried out using X-ray diffraction and scanning electron microscopy. The results showed that it is possible to synthesis zirconium carbide nanopowder with round shape and crystallite sizes smaller than 20 nm at low temperatures. Also according to thermodynamic calculations, it was concluded that by applying vacuum condition, the zirconium carbide formation can occur at less than 1000°C which is very effective on the size reducing of produced ZrC nanopowders.

Synthesis and Forming of Titanium Matrix Composites by Casting Route

2007 ◽  
Vol 334-335 ◽  
pp. 297-300
Author(s):  
Si Young Sung ◽  
Bong Jae Choi ◽  
Young Jig Kim
Keyword(s):  
Electron Microscopy ◽  
Melting Furnace ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Matrix Composites ◽  
Titanium Matrix ◽  
Titanium Matrix Composites ◽  
Electron Probe Micro Analyzer ◽  
Transmission Electron

The aim of this study is to evaluated the possibility of the in-situ synthesized (TiC+TiB) reinforced titanium matrix composites (TMCs) for the application of structural materials. In-situ synthesis and casting of TMCs were carried out in a vacuum induction melting furnace with Ti and B4C. The synthesized TMCs were characterized using scanning electron microscopy, an electron probe micro-analyzer and transmission electron microscopy, and evaluated through thermodynamic calculations. The spherical TiC plus needle-like and large, many-angled facet TiB reinforced TMCs can be synthesized with Ti and B4C by a melting route.

Cycling Stability Performance of La0.75Mg0.25Ni3.5Si0.10 Hydrogen Storage Alloy in Discharge–Charge System

2014 ◽  
Vol 13 (05n06) ◽  
pp. 1460003
Author(s):  
Zhaojiang Liu ◽  
Lei Huang ◽  
Qi Wan ◽  
Xu Li ◽  
Ma Guang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Melting Furnace ◽  
Test System ◽  
Cycling Stability ◽  
Hydrogen Storage Alloy ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Stability Performance ◽  
Charge Discharge

La 0.75 Mg 0.25 Ni 3.5 Si 0.10 hydrogen storage alloy was prepared by vacuum induction melting furnace and subsequently heated treatment at 940°C for 8 h and cooled to room temperature in the oven. The electrochemical properties of La 0.75 Mg 0.25 Ni 3.5 Si 0.10 compound were measured by LAND CT2001A battery test system. The morphologies of the samples were characterized by scanning electron microscopy (SEM). The surface state of samples was analyzed by X-ray photoelectron spectroscopy (XPS). It was found that the charge–discharge rate plays the key impact on the cycling stability of the alloy. During the cycle test, the prepared La 0.75 Mg 0.25 Ni 3.5 Si 0.10 compound presented an excellent capacity retention at the charge–discharge of 1 C while the capacity of sample declined rapidly at 0.2 C. The excellent cycling stability performance of La 0.75 Mg 0.25 Ni 3.5 Si 0.10 electrode at 1 C could be attributed to the less powder and less oxidation of surface effective active elements. The pulverization inevitably leads to the separation of the part of the cracking alloy and the electrode, resulting in reduction of the effective active substance and increasing attenuation of the capacity per cycle. In addition, on the analysis of the different cut-off potential effects on the electrode, it was found that the La 0.75 Mg 0.25 Ni 3.5 Si 0.10 electrode shows good comprehensive electrochemical properties at 1 C cut-off 0.6–0.7 V. During charging, heavy overcharge will not be conducive to cycling stability performance during the charging test.

Deformation of the Aluminum Bath Surface in an Induction Melting Furnace

2015 ◽  
pp. 999-1004
Author(s):  
Akshay Bansal ◽  
Pierre Chapelle ◽  
Yves Delannoy ◽  
Emmanuel Waz ◽  
Pierre Le Brun ◽  
...  
Keyword(s):  
Melting Furnace ◽  
Bath Surface ◽  
Induction Melting

Deformation of the Aluminum Bath Surface in an Induction Melting Furnace

2015 ◽  
pp. 997-1004
Author(s):  
Akshay Bansal ◽  
Pierre Chapelle ◽  
Yves Delannoy ◽  
Emmanuel Waz ◽  
Pierre Le Brun ◽  
...  
Keyword(s):  
Melting Furnace ◽  
Bath Surface ◽  
Induction Melting

Influence of Zr Additive on the Chemical Reduction Behaviour of MoO3 in Carbon Monoxide Atmosphere

2021 ◽  
Vol 317 ◽  
pp. 173-179
Author(s):  
Alinda Samsuri ◽  
Mohd Nor Latif ◽  
Norliza Dzakaria ◽  
Fairous Salleh ◽  
Maratun Ajina Abu Tahari ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Molybdenum Trioxide ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Chemical Effect ◽  
Physical Analysis ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Reduction Behaviour ◽  
Temperature Programmed

Temperature-programmed reduction (TPR) was used to observe the chemical reduction behaviour of molybdenum trioxide (MoO3) and zirconia (Zr)-doped MoO3 catalyst by using carbon monoxide (CO) as the reductant. The characterisation of catalysts was performed by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and transmission electron microscopy (TEM) analyses. The reduction performance were examined up to 700°C and reduction was continued for 60 min at 700°C in a stream of 20 vol. % CO in nitrogen. The TPR profile showed that the doped MoO­3 catalyst was slightly moved to a higher temperature (580°C) as compared to the undoped MoO3 catalyst, which began at around 550°C. The interaction between zirconia and molybdenum ions in doped MoO3 catalyst led to an increase in the reduction temperature. According to characterisation of the reduction products by using XRD, it revealed that the reduction behaviour of pure MoO3 to MoO2 by CO reductant involved two reduction stages with the formation of Mo4O11 as the intermediate product. Meanwhile, MoO3 catalyst doped with zirconia caused a delay in the reduction process and was proven by the presence of Mo4O11 species at the end of reactions. Physical analysis by using BET showed a slight increase in surface area of 3% Zr-MoO3 from 6.85 m2/g to 7.24 m2/g. As for TEM analysis, black tiny spots located around MoO3 particles revealed that the zirconia was successfully intercalated into MoO3 particles. This confirmed that formation of intermetallic between Zr-MoO3 catalyst will give new chemical and physical properties which has a remarkable chemical effect by disturbing the reduction progression of MoO3 catalyst.

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