李维彪
,
王芳
,
齐凤升
,
李宝宽
金属学报
利用旅行薄片微元体能量守恒原理，引入喂钢带相对速度参量，建立了结晶器喂钢带连铸工艺的数学模型。采用有限体积法, 用Visual Basic语言独立编制源码模拟程序，并对一典型喂钢带的连铸工艺进行模拟分析，得到了连铸坯温度分布和喂进钢带凝固状态的曲线。喂进钢带改变了结晶器内温度场的分布和传统的由表及里凝固方式；钢带在结晶器内先凝固后熔化，降低了钢水过热度和铸坯断面温度梯度，使的温度分布更有利于等轴晶结晶过程的进行，有利于铸坯断面形核率的提高。同时该模型也给出了钢带尺寸、拉速和过热度等参数对连铸坯凝固过程的影响，为喂钢带工艺的工业化提供了理论依据。
关键词:
喂钢带
,
continuous casting
,
mold
,
solidification
,
mathematical model
D.F. Wu
,
S.S. Cheng
金属学报(英文版)
Turbulent flow and heat transfer coupled with solidification in slab continuous casting mold was studied by numerical simulation method. Volume of fluid (VOF) model is used to solve steel-air two-phase flow problem and enthalpy-porosity scheme is introduced to solve the fluid flow problem involving solidification. Contributions of various nozzle port angles and port widths and heights on the free surface fluctuation and the thickness of solidifying shell in slab mold were particularly investigated, based on which the structure of submerged entry nozzle was optimized. Flow inside the common nozzle port cannot fill the entire outlet area, having a recirculation in the upper portion of the port, which is enlarged for the nozzle port with both larger height and width. Results show that the flow in mold cavity is mainly controlled by the nozzle port angle. The increase of the angle of upper face of the port to shape a roughly streamlined inner-wall improves the effective area fraction of the nozzle, resulting in less jet impingement, weaker free surface turbulence and thicker solidifying steel shell.
关键词:
continuous casting
,
null
,
null
,
null
G.J. Xu
,
D.H. Li
,
J.C. He
金属学报(英文版)
In order to know the distribution of magnetic field in a novel flow control of mold(NFC Mold) and to provide the experimental data for the electromagnetic structuredesign and the analysis of flow control in continuous casting mold, the magnetic fieldin a NFC Mold were measured by Tesla meter of Model CT-3. The method of vectorsynthesis was adopted in the measurement of magnetic fields. The results showed thatthe magnetic field in the NFC Mold was composed of two main magnetic areas thatwere symmetrical. Although there was leaking magnetic flux between the lower surfaceof the upper pole and the upper surface of the lower pole on the sides, it was restrainedby the main magnetic fields effectively. Therefore the NFC Mold was more preferablysatisfied to be used in controlling the molten steel flow in continuous casting mold.
关键词:
continuous casting
,
null
,
null
,
null
ZHU Xianhua DONG Zengzhang SU Junyi Xi'an Jiaotong University
,
Xi'an
,
China
金属学报(英文版)
The solidification process of a horizontally continuously cast gray iron bar of 4.6cm in diame- ter was modelled.The function describing the distribution of heat flux at the internal surface of graphite sleeve,which was equal to that on the surface of the iron bar,was inversely derived using numerical calculation from the temperature distribution in the sleeve measured in real production.By using the distribution of heat flux as a boundary condition on the surface of the iron bar,the numerical simulation on solidification of the iron bar taking longitudinal heat conduction into account was made.The profile of solidification front obtained from the numer- ical simulation was approximately coincident with that in real production.In addition,the quantitative relationships of the thickness of solidified shell at the exit of the mold to the main technological parameters,including the temperature of liquid iron at the entrance of the mold, the moving speed of the bar and the intensity of water cooling,were obtained from the numeri- cal simulation.
关键词:
continuous casting
,
null
,
null
,
null
T. J. Li(Dalian University of Technology
,
Dalian 116923
,
China)K. Sassa and S. Asai(Nagoya University
,
Nagoya 464-01
,
Japan)
金属学报(英文版)
Contacting state between molten metal and a mold and initial solidification process of continuously cast metals can be controlled by imposing an intermittent magnetic field.In this study, effect of the intermittent magnetic field on the initial solidification ofcontinuoasly cast metals was investigated by measuring the temperature distribution in the melt pool and the initial solidification starting position of shells. It was found that under the condition with intermittent magnetic field, the melt near meniscns is in slow cooling state, the initial solidification starting position descends, initial solidification shell thickens and the liquid-solid interface becomes smooth.
关键词:
continuous casting
,
null
,
null
,
null
Hiroshi Takechi Nippon Steel Corporation
,
Japan.
材料科学技术（英）
This paper reviews recent developments in the contin- uous processing of steels in Japan.The following items are discussed:continuous casting-direct rolling(CC-DR) process of hot-rolled strip:thermomechanical control process(TMCP)of heavy plates:in—line heat treating pro- cess of rails:direct lead patenting(DLP)process of wire rods;and fully integrated processing line(FIPL)of cold-rolled strip.
关键词:
continuous casting
,
null
,
null
,
null
A.Y. Deng
,
J.C. He
金属学报(英文版)
A coupled model including electromagnetic field, fluid dynamic, heat transfer and so-lidification, is developed and applied to the numerical simulation of steel flow andsolidification in a 100mm× 100mm soft-contact mold. In this study, the 3D finite dif-ference method and n, on-staggered grid system for fluid flow with body fitted coordinatewere employed. Numerical results show that the electromagnetic force mainly affectsthe steel flow at upper part of mold, especially in the vicinity of meniscus. There existupward flows covering the surfaces of the billet due to the concentration of electro-magnetic force on the upper part of the billet. This flows join together and form adownward flow near the SEN, so a distinct circulating flow zone is formed at upperpart of mold. After applying electromagnetic force, the steel velocity is improved andthe temperature is raised. The strong stirring of electromagnetic force on liquid steelmakes the kinetic energy on free surface increase. It is clearly seen that the solidifi-cation start point shifts downward in soft contact mold. As a result, the initial shellthickness gets thin and the initial solidification shell length is shortened.
关键词:
continuous casting
,
null
,
null
,
null
,
null
