Study on the burn-out of Ti and Al elements in the electroslag refining process

In this paper the burn-out of the alloying elements Ti, Al in the electroslag refining was studied. The experiment was conducted on laboratory scale electroslag refining (ERS) equipment, the steel grades used in the study contain Ti and Al alloy elements. Experimental results showed that the burn-out ratio of Ti and Al in ESR was quite high. To minimize that ratio, it was possible to apply technological measures such as: using protective gas and selecting of an appropriate slag system, as well as combining additives containing Ti and Al for slag in the refining process. When applying these measures, the burning level of Ti and Al has decreased significantly compared to the previous one (from > 50 % to below 20 %). Especially in case of using the ANF-32 slag + 10 % TiO2 and conducting the operation of ESR under the Ar gas environment, the burn-out ratio of these alloy elements exhibited a negative value.

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Study of the Removal of Boron from Metallurgical Grade Silicon by Oxidation Slagging Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.156-157.882 ◽

2010 ◽

Vol 156-157 ◽

pp. 882-885 ◽

Cited By ~ 3

Author(s):

Yu Yan Hu ◽

Dong Liang Lu ◽

Tao Lin ◽

Yu Liu ◽

Bo Wang ◽

...

Keyword(s):

Removal Efficiency ◽

Orthogonal Experiment ◽

Slag System ◽

Refining Process ◽

Impact Factors ◽

Metallurgical Grade Silicon ◽

Optimum Parameters ◽

Grade Silicon ◽

Refining Time ◽

The Impact

Refining of solar grade silicon by metallurgical method is the research hotspot of polycrystalline field. Slagging method is benefit to the removal of the impurities especially to boron exsisted in the raw silicon. In this study, the influence of the density, the viscosity and liquidus temperature of the slag components on the refining process were discussed, and then the slag system SiO2-Na2CO3 was choosed as the slagging agents. And then the impact factors on the removal efficiency of boron such as the composition of SiO2 and Na2CO3, the ratio of slag to silicon and the refining time were investigated by the orthogonal experiment. The results showed that the optimum parameters of the oxidation refining for removing boron were as follows: the main composition of the oxidant is “SiO2 : Na2CO3 = 60% : 40%”; the slag/silicon ratio is 0.5; time for refining is 60min at 1550 . The results indicated that the removal efficiency of boron was 88.28%, and the content of boron in MG-Si can be reduced to 7ppmw under the best refining process¬.

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Simulation of the External Pressure Influence on the Micro-Structural Evolution of a Single Crystal Ni-Based Superalloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.278.247 ◽

2011 ◽

Vol 278 ◽

pp. 247-252

Author(s):

Inmaculada Lopez-Galilea ◽

Stephan Huth ◽

Suzana Gomes Fries ◽

Ingo Steinbach ◽

Werner Theisen

Keyword(s):

Single Crystal ◽

Microstructural Evolution ◽

Phase Field ◽

Structural Evolution ◽

Field Method ◽

External Pressure ◽

Experimental Results ◽

Alloying Elements ◽

Phase Field Method

The phase field method has been applied to simulate the microstructural evolution of a commercial single crystal Ni-based superalloy during both, HIP and annealing treatments. The effects of applying high isostatic pressure on the microstructural evolution, which mainly retards the diffusion of the alloying elements causing the loss of the orientational coherency between the phases is demonstrated by the simulation and experimental results

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Isothermal Rolling of Mg-Based Laminated Composites Made by Explosion Cladding

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.443.614 ◽

2010 ◽

Vol 443 ◽

pp. 614-619 ◽

Cited By ~ 5

Author(s):

Xin Ping Zhang ◽

Ming Jen Tan ◽

Ting Hui Yang ◽

Jing Tao Wang

Keyword(s):

Finite Element ◽

Composite Material ◽

Elevated Temperature ◽

Magnesium Alloy ◽

Finite Element Methods ◽

Strain Distribution ◽

Experimental Results ◽

Az31 Magnesium Alloy ◽

Al Alloy ◽

Layer Composite

Rolling of Al-Mg-Al tri-layer composite material fabricated by the explosion cladding method was simulated using finite element methods. The rolling temperature was determined based on the flow stresses of AZ31 magnesium alloy and 7075 Al alloy at elevated temperature. The strain distribution in the plates during rolling and effects of the reduction ratio on the separation in the Al/Mg/Al laminate were studied. The simulation agrees with experimental results.

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Effect of Ce2O3 and CaO/Al2O3 on the Phase, Melting Temperature and Viscosity of CaO-Al2O3-10 Mass% SiO2 Based Slags

High Temperature Materials and Processes ◽

10.1515/htmp-2013-0025 ◽

2014 ◽

Vol 33 (1) ◽

pp. 77-84 ◽

Cited By ~ 1

Author(s):

Chengchuan Wu ◽

Guoguang Cheng ◽

Hu Long

Keyword(s):

Melting Temperature ◽

Slag Composition ◽

Slag System ◽

Refining Process ◽

Phase Identification ◽

X Ray Diffraction ◽

Green Color ◽

X Ray ◽

Point Detector ◽

O Phase

AbstractThe melting temperature and viscosity of CaO-Al2O3-10 mass% SiO2 based slag system with various concentrations of Ce2O3 have been studied using the melting point detector and the rotating crucible viscometer. And X-ray diffraction analysis has been used for phase identification. The results show that cerium is stable in Ce3+ state existing mainly as CeAlO3 and Ce4.67(SiO4)3O phase in slags and CeAlO3 phase appears in green color. The melting temperature gently decreases with Ce2O3 additions in 1.57 of CaO/Al2O3. Moreover, the melting temperature increases first and then decreases with the increasing of CaO/Al2O3 from 1.17 to 1.52 at 4.47 mass% Ce2O3. In addition, at 1.57 of CaO/Al2O3, the viscosity increases at the beginning and then decreases with the increasing Ce2O3 content from 4.39 to 11.48 mass%. Furthermore, at 4.47 mass% Ce2O3, the viscosity decreases at the first and then increases with the increasing CaO/Al2O3 from 1.17 to 1.52. Meanwhile, from the slopes of the Arrhenius relationship for viscosity, the activation energy range of viscous flow is from 179.07 to 433.70 kJ/mol. On the basis of these results, slag composition of 45.64 mass% CaO-39.02 mass% Al2O3-10.73 mass% SiO2-3.83 mass% Ce2O3 is melting temperature of 1361 °C and viscosity of 0.398 Pa·s (1500 °C), which has superiority and is more suitable for the actual refining process.

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Site preference of alloying elements in Fe3Al-based alloys

Journal of Materials Research ◽

10.1557/jmr.2001.0054 ◽

2001 ◽

Vol 16 (2) ◽

pp. 344-351 ◽

Cited By ~ 11

Author(s):

Xiao Dong Ni ◽

Nan Xian Chen ◽

Jiang Shen ◽

Zu Qing Sun ◽

Wang Yue Yang

Keyword(s):

Experimental Results ◽

Alloying Elements ◽

Octahedral Interstice ◽

Site Preference ◽

Interatomic Potentials ◽

First Principle ◽

Cr Addition ◽

Good Agreement

On the basis of the first principle interatomic potentials, the site preference of various alloying elements in Fe3Al were evaluated for Ti, Si, Ni, Mn, Mo, and Cr, respectively. The calculated results of the substitutional distribution were in good agreement with the experimental results. Moreover, the calculated results showed that H atoms in Fe3Al prefer to occupy the Fe-type octahedral interstice on the surface, which resulted in concentration of H atoms on the surface. Cr addition decreased the absorbability of Fe3Al-based alloys for H atoms and the force to drive H atoms segregating to surface. The concentration of H atoms on the surface can be decreased by Cr addition.

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Effects of Growth Rates on Directionally Solidified Microstructure of Al-Ni-Y Ternary Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.562-564.477 ◽

2012 ◽

Vol 562-564 ◽

pp. 477-481

Author(s):

Rui Xu

Keyword(s):

Temperature Gradient ◽

Directional Solidification ◽

Ternary Alloy ◽

Growth Rates ◽

Optical Microscope ◽

Experimental Results ◽

Al Alloy ◽

Directionally Solidified ◽

X Ray Diffraction ◽

X Ray

The directional solidification of the ternary Al alloy with composition of 2.6 at%Ni, 0.9 at%Y and 96.5 at% Al was carried out under the temperature gradient of 5 K/mm and the droping velocities of 0.5 mm/min, 1 mm/min, 5 mm/min, 10 mm/min, and 25 mm/min. The microstructure of the Al-Ni-Y ternary alloy was also analyzed by X-ray diffraction and optical microscope. The experimental results show that the microstructures of the Al-Ni-Y ternary alloy are consisted of ª-Al2, Al3Ni and Y4Ni6Al23phase when the alloy was directionally solidified in all directionally solidified rates in the experiments. No primary -Al can be found in the sample with directionally solidified rate of 0.5 mm/min. When the rates higher than 1 mm/min, the primary ª-Al can be observed. The microstructure of the directionally solidified alloy becomes finer and the primary ª-Al is smaller gradually with the increasing of growth velocities when the dropping rate of directional solidification is higher than 5 min/min. Two eutectic structures, Y4Ni6Al23andª-Al eutectic and Al3Ni and ª-Al eutectic, can be found when the dropping rate is higher than 10 mm/min.

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Research on the Preparation and Rheo-Casting of A356 Al Alloy by LSPWES Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.457-458.69 ◽

2012 ◽

Vol 457-458 ◽

pp. 69-73

Author(s):

Man Huan Li ◽

Guo Xing Tang ◽

Wei Min Mao ◽

Yong Feng Liu

Keyword(s):

Proper Time ◽

Great Influence ◽

Injection Pressure ◽

Experimental Results ◽

Temperature Fields ◽

Homogeneous Distribution ◽

Semisolid Slurry ◽

Al Alloy ◽

Injection Speed ◽

Filling Ability

The semisolid slurry of A356 Al alloy was prepared by low superheat pouring and weak traveling-wave electromagnetic stirring (LSPWES), and then the slurry was further soaked for proper time and finally rheo-cast into a rheo-casting sample in this paper. The experimental results show that if the melt of A356 Al alloy is poured at 630-650°C and meanwhile stirred by weak electromagnetic field for a short time, the most primary α-Al grains solidified in the slurry are spherical and only a few are rosette-like. The shape of primary α-Al becomes more spheroidal and more homogeneous distribution in the microstructure by the process of the uniform temperature fields. The experimental results also show that the slurry temperature, injection pressure and speed have a great influence on filling ability. The higher the slurry temperature, injection pressure and speed, the higher the slurry filling ability, the more easily the die cavity is filled. With the given rheo-casting sample, if only the slurry temperature should be equal to or more than 585°C, or the injection pressure is equal to or more than 20 MPa, or the injection speed should be equal to or more than 0.24m/s, the rheo-casting sample die cavity can be filled completely. The microstructure of the castings indicates that the shape, size and numbers of the primary α-Al grains in different parts of the castings are highly consistent. After being held at 535 °C for 5 h and then aged at 160 °C for 16 h, the tensile strength, elongation rate and hardness of the rheo-casting samples with the above process are respectively 321.5 MPa, 8.03% and 105.9HB.

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Three Generations Micro-Allying Steel Processing: Thirty Years of Successive Work at CMRDI

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.835.324 ◽

2020 ◽

Vol 835 ◽

pp. 324-334

Author(s):

Maha El-Meligy ◽

Taher El-Bitar

Keyword(s):

Mechanical Properties ◽

Temper Embrittlement ◽

Steel Plates ◽

Alloying Elements ◽

Recrystallization Temperature ◽

Low Carbon ◽

Alloying Element ◽

Hot Strip ◽

Steel Processing ◽

Steel Grades

The present article presents cumulative works, which were carried out in the field of micro-alloying steel processing at Central Metallurgical R&D Institute (CMRDI) and/or full scale trials in collaboration with the Egyptian steel industry.It was agreed upon defining three main generations of processing micro-alloying steel. The 1stgeneration starts officially on 1975 and continues up to 1995, where it deals with using Ti and V as micro-alloying elements for steel long products. On the year 1985, Central Metallurgical R&D Institute (CMRDI) succeeded to implement of HSLA V-micro-alloyed rebar steel grades at Delta steel mills instead of conventional rebar grades.The 2nd generation was starting on late 1995 and continued to 2005. It was dealing mainly with low carbon content steel (0.04-0.08 %) for flat products (plate and sheet). The most successfully used micro-alloying element was Nb. Beside its precipitate forming effect, Nb is working as substitution solid solution strengthener. Moreover, it raises the recrystallization temperature (Tr). Mainly, micro-alloyed flat steels were developed to fulfill the requirements of the American Petroleum Institute (API) specifications 5L- Product Specification Levels (PSL1) and (PSL2) for manufacturing oil and natural gas pipelines. Meanwhile, a newly born Compact Slab Processing (CSP)-hot strip direct rolling technology was created. On years 2002, the metal forming department in CMRDI succeeded to implement controlled rolling of hot strip Nb-steel sheet at the Compact Slab Process (CSP) Machine in Alexandria National Iron and Steel (ANSDK) Company. Controlled hot rolling schedules were used and followed by early and late cooling at the run out table (ROT). Both contracts were fruitfully succeeded to introduce the API X52 grade at ANSDK Company, followed by X60, and X70 steel grades at Ezz Flat Steel (EFS) Company. The essential mechanical properties of the processed API steel sheets were matched with the API 5L-PSL2 specifications.The 3rd generation was initially developed after 2005 and continued up to day. It deals with micro-alloying with special functional elements like Boron (B). Boron was favored as a micro-alloying element for bilateral effects. Boron carbide (B4C) precipitates are the hardest after diamond, which would be reflected on raising the mechanical properties of the steel. Moreover, Boron was favorably used because it delays the temper embrittlement phenomena. On year 2014, the National for Military Industrialization authority requested from CMRDI to collaborate with Military Factory 100 to develop a technology package for processing armor steel plates. Trials were started with a 3rd generation B-micro-alloyed steel alloy. Many other alloying elements were used beside Boron to develop extra high strength 6.0 mm thickness plates. Finish hot rolled plates were then subjected to a subsequent water quenching from 900 °C and followed by tempering at 250 °C for 20 min. Representation 50X50 cm2 steel plates were successfully passed after 3 bullets in front and 3 bullets rear shooting.

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Failure Analysis and Elimination of Galvanic Corrosion on Bondpads During Wafer Sawing

ISTFA 2000: Conference Proceedings from the 26th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2000p0369 ◽

2000 ◽

Author(s):

Y. N. Hua ◽

E. C. Low ◽

L. H. An ◽

Shailesh Redkar

Keyword(s):

Failure Analysis ◽

Feed Rate ◽

Galvanic Corrosion ◽

Experimental Results ◽

Metal Corrosion ◽

Wafer Fabrication ◽

Al Alloy ◽

Assembly Process ◽

Water Problem ◽

Sawing Process

Abstract In our previous paper [1], discolored bondpads due to galvanic corrosion were studied. The results showed that the galvanic corrosion occurred in 0.8 ìm wafer fabrication (fab) process with cold Al alloy (Al-Si, 0.8 wt%-Cu, 0.5 wt%) metallization. Galvanic corrosion is also known as a two-metal corrosion and it could be due to either wafer fab process or assembly process. Our initial suspicion was that it was due to a DI water problem during wafer sawing at assembly process. After that, we did further failure analysis and investigation work on galvanic corrosion of bondpads and further found that galvanic corrosion might be due to longer rinsing time of DI water during wafer sawing. The rinsing time of DI water is related to the cutting time of wafer sawing. Therefore, some experiments of wafer sawing process were done by using different sizes of wafer (1/8 of wafer, a quadrant of wafer and whole of wafer) and different sawing speed (feed-rate). The results showed that if the cutting time was longer than 25 minutes, galvanic corrosion occurred on bondpads. However, if the cutting time was shorter than 25 minutes, galvanic corrosion was eliminated. Based on the experimental results, it is concluded that in order to prevent galvanic corrosion of bondpads, it is necessary to select higher feed-rate during wafer sawing process at assembly houses. In this paper, we will report the details of failure analysis and simulation experimental results, including the solution to eliminate galvanic corrosion of bondpads during wafer sawing at assembly houses.

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