Na LI
,
Zhenyu LIU
,
Yiqing QIU
,
Zhaosen LIN
,
Xianghua LIU
,
Guodong WANG
,
null
,
null
,
null
,
null
,
null
,
null
材料科学技术（英）
In the present paper, low carbon steel strips with different phosphorus contents were produced using a twin roll strip casting process. The solidification structure was studied and its features were analyzed in detail. It was found that the strips possessed a fine microstructure compared with the mould cast steels. With increasing phosphorus content more ferrite has been formed with finer grains.
关键词:
hosphorus
,
Solidification
,
structure
,
Stri
Jianzhong XU
,
Dianyao GONG
,
Wencai ZHANG
,
Xianwen CHANG
,
Xianghua LIU
,
Guodong WANG
材料科学技术（英）
The code for calculating the crown effect rate of hot strip steel was developed using the effect function method. The effect of the initial crown on the crown of the product in hot strip rolling was investigated. The coefficients of a polynomial of degree six for calculating the base value of initial crown effect rate in 4-high mill were determined and the compensation factors of per unit width rolling force, bending force, work roll crown and draft on the initial crown effect rate were given. The difference between the calculation result by established model and theoretical value obtained by effect function method was 4.88 μm when the strip width was 1.85 m.
关键词:
4-high mill
,
null
,
null
,
null
Jianzhong XU
,
Dianyao GONG
,
Xianghua LIU
,
Guodong WANG
,
Xiaolin ZHAO
材料科学技术（英）
Software for calculating the strip profile in 4-high hot rolling mill was developed using influence coefficient method. Regularity of backup roller diameter effect rate was studied systematically using the software. The results show that backup roller diameter effect rates decrease versus the increase of strip width, increase significantly versus the increase of backup roller diameter and obscurely increase versus the increase of reduction. The difference between backup roller diameter effect rate and it is reference value increases versus strip width increasing. When backup rollers diameter is set to be 1.64 m and strip width is 1.85 m, the error of strip profile calculated using the model of backup roller diameter effect rate reference value will be 3.55 μm. Based on the results, reference values of roller diameter effect rate and six power polynomial fitting coefficients of modification coefficients were determined considering coherent parameters. The high precision model of backup roller diameter effect rate was established. When the model is used to predict strip profile, the accuracy is less than 5.0 μm.
关键词:
4-high mill
,
null
,
null
,
null
Peiwei BAO
,
Hongshuang DI
,
Aiwen QIAN
,
Xiaoming ZHANG
,
Guodong WANG
材料科学技术（英）
The 3-dimension numerical simulation study on the electromagnetic dam used in the twin roll caster has been performed by using the edge element method. It was found that the materials and structures of the roll collars have great influence on the distribution of the magnetic flux density, eddy current density and the electromagnetic force in the molten pool. The conductive collars make the magnetic flux density decreased in the molten pool, but it also makes the magnetic force more uniformly, and the force in the low part of the molten pool where needs greater force have increased some what. The conductive collars make the EMD device more effective than the nonconductive collars.
关键词:
Simulation
,
null
,
null
,
null
Hongshuang DI
,
Xiaoming ZHANG
,
Guodong WANG
,
Xianghua LIU
材料科学技术（英）
The M2 high-speed steel strip was produced by using the laboratory scale twin roll strip caster. The microstructure and eutectic carbide morphology of thus produced products were observed and analyzed, and the comparison of those with conventional products was carried out. The effects of the processing parameters such as the melting temperature, the pouring temperature, rolling speed and separating force on the microstructure and eutectic carbide morphology and their distribution were analyzed. The spheroidizing process of the strips in the annealing process was investigated. The relations between the growth and spheroidizing of the eutectic carbide and the annealing technology were obtained, and the mechanism of the twin roll strip casting process improving the eutectic carbide spheroidizing was discussed. The theoretical instruction for determining the subsequent treatment process was provided.
关键词:
Twin roll strip casting
,
null
,
null
,
null
Peiwei BAO
,
Peijie LI
,
Hongshuang DI
,
Xianghua LIU
,
Guodong WANG
材料科学技术（英）
Two types of electromagnetic edge dams were analyzed by using finite element method in present paper. The magnetic vector potential method and edge element method were used. The distributions of the magnetic field, the eddy current intensity and the magnetic force were obtained from the computing. The differences in these fields were explained according to the two types of electromagnetic dam, and characters of their application in twin roll casting were also discussed.
关键词:
Twin roll casting
,
null
,
null
Yunbo XU
,
Yongmei YU
,
Xianghua LIU
,
Guodong WANG
材料科学技术（英）
On the basis of transformation kinetics and thermodynamics, the austenite-ferrite transformation start temperature during deformation was predicted for several grades of low-carbon steels under different processing conditions. Results indicate that Ar3d temperature mostly depended on alloying composition and processing parameters. Ar3d increased as strain rate or strain increased for the same steel grade. In view of enhancement of deformation on transformation, the basic kinetics model was established to simulate deformation induced transformation behavior, using which the influence of the deformation stored energy and effective deformation ledge on the nucleation and growth can be considered. The simulated results are in good agreement with experiment results.
关键词:
Computer simulation
,
null
,
null
,
null
Yunbo XU
,
Yongmei YU
,
Xianghua LIU
,
Guodong WANG
材料科学技术（英）
An integrated metallurgical model was developed to predict microstructure evolution and mechanical properties of low-carbon steel plates produced by TMCP. The metallurgical phenomena occurring during TMCP and mechanical properties were predicted for different process parameters. In the later passes full recrystallization becomes difficult to occur and higher residual strain remains in austenite after rolling. For the reasonable temperature and cooling schedule, yield strength of 30 mm plain carbon steel plate can reach 310 MPa. The first on-line application of prediction and control of microstructure and properties (PCMP) in the medium plate production was achieved. The predictions of the system are in good agreement with measurements.
关键词:
Thermo-mechanical control process
,
null
Jinxia LI
,
Xianghua LIU
,
Guodong WANG
材料科学技术（英）
The relationships among the deformation, texture and deep drawing properties of IF steel were investigated. By adopting double cold rolling (DCR) technology, the deep drawing property has been developed evidently. With the aid of orientation distribution function (ODF) analysis, it was found that the main reason for good property is the counterbalance in intensity of the ideal texture component {111}<011> and {111}<112>.
关键词:
Texture
,
null
,
null
,
null
Zhenyu LIU
,
Guodong WANG
,
Toshio Narita
材料科学技术（英）
In the present paper, a numerical modeling was developed to simulate the growth kinetics of ferrite transformed from austenite in Fe-C-∑X (X denotes substitution elements, such as Mn, Ni, Cr etc.) steels by solving the diffusion equation using finite difference method (FDM). Coupled with the kinetic modeling, thermodynamic calculations were carried out to determine the γ/α phase equilibrium conditions using a para-equilibrium (PE) model. The dissipation of free energy for γ→α phase transformation due to the so-called solute drag effect (SDE) was taken into account in the thermodynamic modeling. With this modeling, simulations on the growth kinetics of ferrite in the steels containing austenite-stabilizing and ferrite-stabilizing elements (such as Ni, Mn and Si, Cr, respectively) were performed, which indicates that it deviates from the parabolic growth rate law after the initial stage of transformation. The results were compared with the experimental values given by Bradley and Aaronson, showing that this model has a reasonably good accuracy to predict the growth kinetics of ferrite.
关键词:
Numerical modeling
,
null
,
null
,
null
