JIANG Qichuan HE Zhenming YAN Jiulin CUI Donghuan WANG Shoushi Jilin University of Technology
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Changchun
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China JIANG Qichuan Associate Professor
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Faculty of Casting Technology
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Jilin University of Technology
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Changchun 130025
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China
金属学报(英文版)
The needle-like and network carbides in as-cast high carbon wear-resistant manganese steels will be nodularized and dispersed,by a large majority,in austenite aider modifying treatment with Mg system agents.The impact toughness of the steels is significantly improved and the hardness is also increased to a certain extent.As a result,the steels can be used in as-casted state without any heat treatment and their wear resistance can be greatly enhanced.
关键词:
Mg modification
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null
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null
C Gheorghies
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I Crudu
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C Teletin
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C Spanu
钢铁研究学报(英文版)
A theoretical model adapted for studying steel continuous casting technology was proposed. The model based on system theory contained input/output, command, and control parameters. The process was divided into five stages, ie, tundish, mold, guiding system, guidingdrawing system, and guidingdrawingsoft reduction system. The model can be used to describe the physicochemical processes, thermal processes, chemical processes, and characteristics of the cast material according to the abovementioned stages. It can also be applied to other metallurgical technologies and even to other industries (chemistry, food, etc).
关键词:
steel;casting technology;system theory;modeling
Huiguan WAN
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Xiumei QI
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Jing TIAN
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Yuyong CHEN
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Weiqiang ZHA
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Jun JIA
材料科学技术（英文）
In this research, the materials and the compositions of the surface slurries were chosen by considering the characteristics of Ti investment casting. The effects of solid-liquid ratios on the properties of the slurry and the effects of baking temperatures on the flexural strength have also been investigated. Flawless shells having smooth inner surface were manufactured with proper technology. Ti and its alloys were melted and poured by water-cooled Cu crucible vacuum induction furnace. The qualities of the investment castings made accordingly were studied and analyzed.
关键词:
CHEN Yong
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et al
钢铁研究学报(英文版)
The dynamic soft reduction technology for 360mm×450mm bloom casting and its application results at PISCO (Panzhihua Iron & Steel Co.) were presented. In order to analyze the influence of the soft reduction on internal defects of bloom, such as center porosity and central segregation, experiment for contrasting process with or without soft reduction for bloom was investigated. The operation shows that after applying the soft reduction of bloom alloy steel, the ratio of center porosity whose defect level is below 1.0 increased from 66.67% to 85.71%, ratio of central segregation whose defect level is below 1.0 increased from 94.44% to 100%, ratio of central shrinkage cavity which is free increased from 88.89% to 96.42%, and central segregation index of carbon decreased from mean value of 1.15 to 1.05. These results have provided important technology supports for PISCO to optimize the steel product structure, and to improve the production of high quality, property, and value added products.
关键词:
continuous casting bloom;dynamic soft reduction;alloy steel;internal quality
Peng ZHANG
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Yunhui DU
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Daben ZENG
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Jianzhong CUI
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Limin BA
材料科学技术（英文）
For the first time, the distribution of graphite particles in QTi3.5-3.5 graphite ingot was studied by using semi-solid casting technology. The results show that: the relationship between solid fraction and stirring temperature of QTi3.5-3.5 graphite slurry is y=759.4-0.711x (where y is solid fraction, x is stirring temperature). With the increasing of solid fraction of QTi3.5-3.5 graphite slurry, the agglomeration of graphite particles in ingot reduces gradually. The condition to prepare QTi3.5-3.5 graphite lubricant material with even distribution of graphite particles is that the solid fraction of QTi3.5-3.5 graphite slurry is larger than 40%.
关键词:
Min ZHAO
材料科学技术（英文）
TiB2P/Al composite was successfully fabricated by squeeze casting technology. Its mechanical and tribological properties were evaluated. The elimination of Ti-Al intermetallic compound was confirmed by X-ray diffraction (XRD) studies. At 45% volume fraction, the bending strength at ambient temperature was 934 MPa. And the fracture modes included ductile failure of Al matrix and brittle fracture of TiB2 particles. In dry sliding wear mode, severe plastic deformation and adhesive wear were found on the worn surfaces of the SiCP/Al composite. But no obvious characteristics of adhesion or abrasion wear were observed on that of the TiB2P/Al composites. At the steady stage, the friction coefficient of the SiC2P/Al composite was about 0.6. While that of TiB 2P/Al composite was only about 0.16~0.17.
关键词:
TiB2
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null
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null
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null
Chang-Seog Kang
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Jae-Ik Cho
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Chang-Yeol Jeong
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Se-Weon Choi
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Young-Chan Kim
材料科学技术（英文）
Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties. However, manufacturing of thin-walled aluminum die-casting components, less than 1.0 mm in thickness, is generally known to be very difficult task to achieve aluminum casting alloys with high fluidity. Therefore, in this study, the optimal die-casting conditions for producing 297 mm×210 mm×0.7 mm thin-walled aluminum component was examined experimentally by using 2 different gating systems, tangential and split type, and vent design. Furthermore, computational solidification simulation was also conducted. The results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after solidification. It was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion.
关键词:
Aluminum
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null
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null
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null
L.L. Chen
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R.X. Liu and H.T. Lin College of Materials Science and Engineering
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Huazhong University of Science and Technology
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Wuhan 430074
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China
金属学报(英文版)
In this paper, the development status of casting numerical simulation technology is introduced. In additional, mathematical model, solution method, initial condition, boundary condition and defect predicting scheme of foundry process are also analyzed, which include the mold filling process, solidification process and the process coupling fluid flow with heat transfer. Finally, a practical casting is taken out to show how to predict defects and optimize foundry process with numerical simulation technology.
关键词:
foundry
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null
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null
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null
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null
Z. X. Lee
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F. P. Huang and W. Y. Zhang Tianjin University
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Tianjin 300072
,
China
金属学报(英文版)
Using Fourier's conduction equation, a mathematical model of the temperature field for the coat of coat-cast technology is established. The relationship between the thickness, quality of the coat and casting temperature of liquid iron is analyzed. The results show that the coat quality is reliable; the combination of the coat with the base is solid; because foe temperature gradient of the coat is not large, the surface, middle and bond area of the coat are melted completely and the thickness of the coat can reach 2.3mm by using self-melting spraying alloy powder when the casting temperature is higher than 1380℃. In addition, the agreement between the calculated and measured values is good. This paper is of significant meaning for coat-cast technology and the coat quality.
关键词:
coat-cast
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null
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null
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null
