Production of Magnesium Alloy Billets by Semisolid Continuous Casting

2009 ◽  
Vol 610-613 ◽  
pp. 1403-1406 ◽  
Author(s):  
Futoshi Kido ◽  
Tetsuichi Motegi
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Continuous Casting ◽  
Mobile Phone ◽  
Electric Furnace ◽  
Copper Mold ◽  
Cooling Plate ◽  
Continuously Cast ◽  
The Difference ◽  
Molten Magnesium

In order to produce AZ91 and AZ31 magnesium alloy billets semisolid continuous casting by using an inclined cooling plate was carried out. The molten magnesium alloy in an electric furnace was flowed on the inclined cooling plate and then poured in a tundish. The slurry prepared using this process was solidified by drawing a dummy bar from a water-cooled copper mold, consequently producing a billet. As a result, we could produce the magnesium alloy billets by semisolid continuous casting. Magnesium alloy billets with refined and globular primary α crystals were successfully and continuously cast by optimizing the solidification conditions. In this case, the grain size of AZ91 billets was about 55μm and that of AZ31 billets was 50μm. The AZ91 billets produced by semisolid continuous casting were employed in thixocasting experiments. The experiments revealed that thixocasting could produce the mobile phone casings with spherical primary α crystals at 858K. Moreover, we proved that the difference of shot cycle did not influence the microstructures for up to 251 shots.

Refinement Effect and Mechanism of AZ31 Magnesium Alloy by Electromagnetic Stirring under the Effect of Grain-Refiner

2013 ◽  
Vol 631-632 ◽  
pp. 556-561 ◽  
Author(s):  
Sheng Yuan Gao ◽  
Shi Lian Qu ◽  
Yue Yuan ◽  
Bao Qin Fu
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Heterogeneous Nucleation ◽  
Holding Time ◽  
Electromagnetic Stirring ◽  
Az31 Magnesium Alloy ◽  
Grain Refiner ◽  
Nucleation Sites ◽  
Continuously Cast ◽  
Refinement Effect

The effects of electromagnetic stirring and Al4C3grain refiner on the grain refinement of semi-continuously cast AZ31 magnesium alloy were discussed in this investigation. The results indicate that electromagnetic stirring has effective refining effect on the grain size of AZ31 magnesium alloy under the effect of Al4C3grain refiner. Electromagnetic stirring can “activate” the Al4C3particles, resulting in more heterogeneous nucleation sites for the primary α-Mg grains. But, longer holding time can “inactivate” the Al4C3particles, and the optimal experimental holding time is 60 min in the present investigation. The activated rate of the electromagnetic under the experimental condition ρ2=1.65%.

scholarly journals Directions of development of production of small- size billets for long products

2018 ◽  
pp. 259-274
Author(s):  
V.G. Gerasimenko ◽  
L.S. Molchanov
Keyword(s):  
Continuous Casting ◽  
Rolling Mill ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Transfer Scheme ◽  
Effective Option ◽  
Continuously Cast ◽  
The Difference ◽  
High Temperature Furnaces ◽  
Decarburized Layer

The aim of the work is to study the technological features of the transfer of metallurgical enterprises to the production of small-size and wire metal products from continuously cast billets. The main parameters of the rolling technology are considered: the size of the billet, the choice of the location of the continuous casting machine, the transfer scheme of continuously cast billets to small- size and wire mills. It is shown that when using a continuously cast square billet with a size of 130x130 mm and 150x150 mm, direct combination of a continuous casting machine with a rolling mill is almost impossible due to the difference in the speed of continuous casting and the roughing group of the mill. The performed calculations show that the scheme of cutting the billets and combining with the intermediate furnace is technologically feasible, however, further heating of the billets leads to significant energy losses. It has been established that an effective option for combining the continuous casting machine with a rolling mill is to use a complex of equipment with a furnace-thermostat for a billets 120 m long. This flowchart reduces the energy consumption for heating the billets by at least 53%. The proposed technology of combining the continuous casting machine with a rolling mill will provide metal savings by reducing the thickness of the scale to 0.4-0.73 mm (an average of 1.1% of the mass of the billet), improve its quality by reducing the depth of the decarburized layer from 1.1 mm to 0.3 mm. The technology provides for the transportation of liquid steel in the ladle from the steel-smelting shop, casting on the continuous casting machine, identification of defects in the billets in a hot condition, supply of the billets with a temperature of 8500С to high-temperature furnaces for heating and subsequent rolling.

Microstructure of AZCa912 Continuous Casting Bar after Hot Compression

2016 ◽  
Vol 879 ◽  
pp. 2567-2572 ◽  
Author(s):  
Akira Watazu ◽  
Naoki Omura ◽  
Kenji Miwa
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Continuous Casting ◽  
Direct Chill ◽  
Hot Compression ◽  
Casting Method ◽  
Dendrite Structure ◽  
Metallic Luster ◽  
Grain Sizes ◽  
Hot Compression Test

AZCa912, 8.8mass%Al-0.68mass%Zn-0.25mass%Mn-1.9mass%Ca-Bal.Mg, continuous casting bars with 50 mm in diameter were formed by a direct chill continuous casting method. AZCa912 alloy is a noncombustible magnesium alloy. The surfaces of the bars had excellent metallic luster. A dendrite structure with a DAS of around 11-23 μm and grain sizes of about 200 μm was observed. Samples with almost the same grain size and different DAS were measured at hot compression test at 250-350°C, 0.01-1/s. Crack on the side surfaces of the samples were not formed by compression at 350°C, 0.01-0.1/s. All samples had an unchanged casting structure after hot pressing, and the percent of the structure remaining unchanged decreased with low-temperature compression and wide DAS.

Grain Refinement of Mg-Y-Zn Alloy by Friction Stir Processing

2007 ◽  
Vol 26-28 ◽  
pp. 465-468 ◽  
Author(s):  
Taiki Morishige ◽  
Masato Tsujikawa ◽  
Sachio Oki ◽  
M. Kamita ◽  
Sung Wook Chung ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Friction Stir Processing ◽  
Az31 Alloy ◽  
Frictional Heat ◽  
Light Metals ◽  
Friction Stir ◽  
The Difference ◽  
Zn Alloy

Grain refinement of magnesium alloy by Friction Stir Processing (FSP) was investigated. It is assumed that dynamic recrystallization (DRX) is occurred by frictional heat and plastic flow during FSP. This process is the effective method of the grain refinement for light metals. In this study, FSP was conducted to cast Mg alloys for and the difference of the grain refinement by DRX in these alloys was examined. As a result, in comparison with commercial Mg-Al-Zn alloy and Mg-Y-Zn alloy have finer microstructure. The grain size of FSP-ed Mg-Y-Zn alloy was ~1.7 [/m], however, that of AZ31 alloy was 20~30 [/m].

Effect of Physical Fields on Solidification Structures of DC Casting AZ80 Magnesium Alloy Billets

2011 ◽  
Vol 105-107 ◽  
pp. 1616-1619
Author(s):  
Zhi Qiang Zhang ◽  
Qi Chi Le ◽  
Jian Zhong Cui
Keyword(s):  
Magnesium Alloy ◽  
Continuous Casting ◽  
Low Frequency ◽  
Direct Chill ◽  
Ultrasonic Fields ◽  
Electromagnetic Casting ◽  
Az80 Magnesium Alloy ◽  
Continuously Cast ◽  
Dc Casting ◽  
Physical Fields

AZ80 magnesium alloy was semi-continuously cast under different physical fields which were conventional direct chill (DC) casting, low frequency electromagnetic casting (LFEC), ultrasonic casting (USC) and electromagnetic-ultrasonic combined casting (ECUC), respectively. The effect of different physical fields on solidification structures of AZ80 alloys was investigated. The results show that compared with the conventional DC casting, structures of AZ80 alloys billets cast with LFEC and USC have been greatly refined. The effective refinement takes place in the edge of billets when LFEC is applied. However, the effective refinement takes place in the center of billets when USC is applied. When combination of low frequency electromagnetic and ultrasonic fields is applied during semi-continuous casting AZ80 magnesium alloy billet, structures of AZ80 alloys are refined significantly in the whole billets everywhere and more uniform.

Influence of technology parameters of free-cutting steel continuous casting on the billet internal structure

2020 ◽  
Vol 76 (2) ◽  
pp. 139-142
Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova
Keyword(s):  
Regression Analysis ◽  
Continuous Casting ◽  
Internal Structure ◽  
Sulfur Content ◽  
Manganese Content ◽  
High Quality ◽  
Correlation And Regression Analysis ◽  
Cutting Steel ◽  
Continuously Cast

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.

BLACK DIAMOND STANDARD

Alloy Digest ◽  
1975 ◽  
Vol 24 (1) ◽  
Keyword(s):  
Grain Size ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tool Steel ◽  
Electric Furnace ◽  
Heat Treating ◽  
Case Depth ◽  
Specialty Metals ◽  
Lower Carbon

Abstract BLACK DIAMOND STANDARD is an electric-furnace-melted, water-hardening carbon tool steel with an excellent reputation for use as the standard in general shop tools requiring extreme toughness and resistance to shock and impact. In the lower carbon ranges (0.50-0.70% carbon), it is used primarily for tools such as pins, punches, hammers and sledges. Black Diamond may be expected to give uniform and consistent results, although no definite limits of case depth or grain size are regularly guaranteed. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: TS-281. Producer or source: Crucible Specialty Metals Division, Colt Industries.

scholarly journals Changes in Paleovegetation and Paleoclimate in China Since the Late Middle Pleistocene: A Case Study of the Dajiuhu Basin

2021 ◽  
Vol 13 (9) ◽  
pp. 4848
Author(s):  
Liwei Wu ◽  
Xinling Li ◽  
Qinghai Xu ◽  
Manyue Li ◽  
Qiufeng Zheng ◽  
...  
Keyword(s):  
Grain Size ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Central China ◽  
Middle Pleistocene ◽  
Pollen Record ◽  
The Difference ◽  
Late Middle Pleistocene

The East Asian monsoon system is an important part of global atmospheric circulation; however, records of the East Asian monsoon from different regions exhibit different evolutionary rhythms. Here, we show a high-resolution record of grain size and pollen data from a lacustrine sediment core of Dajiuhu Lake in Shennongjia, Hubei Province, China, in order to reconstruct the paleovegetation and paleoeclimate evolution of the Dajiuhu Basin since the late Middle Pleistocene (~237.9 ka to the present). The results show that grain size and pollen record of the core DJH-2 are consistent with the δ18O record of stalagmites from Sanbao Cave in the same area, which is closely related to the changes of insolation at the precessional (~20-kyr) scale in the Northern Hemisphere. This is different from the records of the Asian summer monsoon recorded in the Loess Plateau of North China, which exhibited dominant 100-kyr change cyclicities. We suggest that the difference between paleoclimatic records from North and South China is closely related to the east–west-oriented mountain ranges of the Qinling Mountains in central China that blocked weakened East Asia summer monsoons across the mountains during glacial periods.

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