DENG Anyuan
,
WANG Engang
,
XU Yongyi
,
ZHANG Xingwu
,
HE Jicheng
钢铁研究学报(英文版)
The free surface waves of a molten lowmelting point Sn32%Pb52%Bi alloy under the imposition of an AC and a static magnetic field were visualized and recorded by use of a laser displacement sensor and a high speed video camera. The Fourier analysis method was used to analyze the oscillation characteristics. The results show that at the center of the free surface, the azimuthal and radial oscillation mode can be found simultaneously owing to AC magnetic field. With increasing coil current intensity, the amplitude and the main frequencies of the oscillations increase, and the azimuthal fluctuation at the center of the free surface is also enhanced. The fluctuation characteristics are closely related to the turbulent flow induced by the alternating electromagnetic force. A series of regular traveling waves can be observed on free surface, and the main frequencies of oscillations at threephase points decrease owing to superposing AC and static magnetic field. The static magnetic field can remarkably control the unstable swinging behavior of free surface. With increasing static magnetic flux density, the amplitude of oscillations at the center of free surface decreases firstly, and then increases, but the fluctuation amplitude at the triplephase point always reduces and keeps within 1 mm, and the azimuthal waves at the center of free surface are weakened. Especially at 144 T, the radial waves are dominant. The static magnetic flux density should be controlled in an appropriate range to obtain more stable free surface. With compound magnetic field, even if the static magnetic flux density is above 10 T, the free surface still vibrates with lower amplitude and dominant frequency.
关键词:
continuous casting
,
compound magnetic field
,
free surface
,
fluctuation
JIANG Li-hong
,
WANG Ai-guo
,
TIAN Nai-yuan
,
ZHANG Wei-cun4
,
FAN Qiao-li4
钢铁研究学报(英文版)
The continuous casting technological parameters have a great influence on the secondary dendrite arm spacing of the slab, which determines the segregation behavior of materials. Therefore, the identification of technological parameters of continuous casting process directly impacts the property of slab. The relationships between continuous casting technological parameters and cooling rate of slab for spring steel were built using BP neural network model, based on which, the relevant secondary dendrite arm spacing was calculated. The simulation calculation was also carried out using the industrial data. The simulation results show that compared with that of the traditional method, the absolute error of calculation result obtained with BP neural network model reduced from 0.015 to 0.0005, and the relative error reduced from 6.76% to 0.22%. BP neural network model had a more precise accuracy in the optimization of continuous casting technological parameters.
关键词:
continuous casting
,
technological parameter
,
secondary dendrite arm spacing
,
BP neural network
王文军
,
朱志远
,
李战军
,
刘洋
,
李景光
,
刘金刚
钢铁
对首秦2号板坯连铸机轻压下工艺进行了细致的研究。通过连铸坯射钉试验对首秦2号连铸机二级冷却模型进行了校验；通过不同轻压下率试验条件下连铸坯中心偏析的程度确定了合理的、能够有效改善连铸坯中心偏析的轻压下率；通过连铸坯厚度方向不同部位碳硫元素的分析对轻压下工艺改善前后连铸坯中心偏析度进行了对比。结果表明：首秦2号连铸机二级冷却模型能够准确反映连铸坯凝固末端的位置。在拉速为0.70m/min的连铸工艺条件下，320mm厚连铸坯轻压下段为第9和第10段，合理的轻压下率应该保持在0.85～1.0mm/m之间。采用合理的轻压下工艺后，连铸坯中心偏析得到了明显改善，满足了首秦高品质中厚板对连铸坯内部质量的严格要求。
关键词:
连铸
,
slab
,
soft reduction
,
centerline segregation
刘欣
连铸
针对连铸过程中时常发生的坯壳和结晶器铜板壁黏结情况，分析了保护渣性能、结晶器流场、保护渣充填操作、中间包温度、钢水纯净度等造成黏结的各种因素，通过采取相应措施，大大减少了黏结情况。
关键词:
连铸
,
slab
,
bond
,
mould powder
李云涛，张立，徐红伟
钢铁研究学报
结晶器喂带技术通过控制熔体温度场的分布、抑制柱状晶生长来改善连铸坯的成分偏析、芯部疏松等缺陷。通过试验设计系统研究了不同厚度钢带在钢液中的熔化过程以及钢带喂入比对铸坯组织的影响。结果表明：钢带在恒温钢液中的熔化过程分为两个阶段，开始时钢带残余厚度随喂入时间快速增加，增加比达到100%；钢带厚度达到最大值后开始缓慢减小，直到钢带在钢液中全部溶化，此时钢带残余厚度变为零。钢带原始厚度和钢液过热度影响钢带融化终点时间，随着厚度增加和过热度减小，融化终点时间延长；研究钢带厚度范围内，最大融化时间小于100s，过热度增加没有改变钢带融化规律。钢带喂入比影响铸坯等轴晶率和等轴晶晶粒大小，钢带喂入比从0%增加到3%，铸坯等轴晶率从493%增加到753%，提高了527%；平均等轴晶晶粒尺寸减小554%，等轴晶晶粒尺寸达到41mm。钢带喂入比过大导致铸坯芯部疏松缺陷，钢带合适喂入比为1%。
关键词:
连铸
,
strip feeding
,
equiaxed grain ratio
,
melted process
朱正海
,
肖丽俊
,
彭世恒
,
王强
,
干勇
钢铁研究学报
针对连铸过程铌钛微合金钢中第二相在固液两相区和奥氏体内的复合析出行为,通过近似处理建立了多元第二相复合析出的热力学模型,并利用模型研究了X80,E36,J55钢中第二相的析出行为.结果表明:在凝固过程不同的Ti/N摩尔比对液相中Ti,C,N元素的变化影响显著,先析出的第二相对后析出的第二相影响显著,成分高低的差异不但导致第二相析出量的不同,而且也导致析出相种类的不同,碳氮化物在析出的过程中C,N元素摩尔分数的变化受析出温度和钢中元素含量的影响.
关键词:
连铸
,
微合金钢
,
碳氮化物
,
析出
,
热力学模型
