胎圈钢丝中间热处理的工艺参数优化

为减少胎圈钢丝拉拔生产过程中的断丝现象,提高加工性能和最终产品质量,研究了加热温度、铅浴温度和淬火速度等工艺参数对胎圈钢丝性能的影响。结果表明,当φ3.5 mm钢丝的热处理线速度为18 m/min、钢丝出线温度为940 ℃左右时,可得到均匀一致的奥氏体组织,并能在铅槽处理中进一步分解获得要求的索氏体组织,使中间道次钢丝达到最大抗拉强度,有利于减少后续道次的拉拔断丝现象。此工艺下的钢丝在拉拔后,在完成奥氏体均匀化后晶粒没有继续长大,既保证了钢丝组织的均匀,也防止了钢丝抗拉强度的降低。     

More effective removal of oxide inclusions from rail steel in the intermediate ladle

Thermodynamic analysis of the transition of nonmetallic inclusions from metal to slag shows that, in this transition, breakaway of the inclusions from the metal is thermodynamically impossible and the inclusions accumulate at the interface on the slag side. This obstructs subsequent inclusions arriving at the interface and hinders their removal from the steel. Therefore, the successful assimilation of inclusions by the slag calls for the renewal of the slag layer adjacent to the metal by kinetic means—for example, by injecting inert gas into the steel. Industrial tests of argon injection into the steel in the intermediate ladle in casting confirm that the content of oxide inclusions in the rails is reduced.     

Study of the deoxidation of steel with aluminum wire injection in a gas-stirred ladle

In the present work, the deoxidation of liquid steel with aluminum wire injection in a gas-stirred ladle was studied by mathematical modeling using a computational fluid dynamics (CFD) approach. This was complemented by an industrial trial study conducted at Uddeholm Tooling AB (Hagfors, Sweden). The results of the industrial trials were found to be in accordance with the results of the model calculation. In order to study the aspect of nucleation of alumina, emphasis was given to the initial period of deoxidation, when aluminum wire was injected into the bath. The concentration distributions of aluminum and oxygen were calculated both by considering and not considering the chemical reaction. Both calculations revealed that the driving force for the nucleation fo Al₂O₃ was very high in the region near the upper surface of the bath and close to the wire injection. The estimated nucleation rate in the vicinity of the aluminum wire injection point was much higher than the recommended value for spontaneously homogeneous nucleation, 10³ nuclei/(cm³/s). The results of the model calculation also showed that the alumina nuclei generated at the vicinity of the wire injection point are transported to other regions by the flow.     

Influence of carburization of the intermediate product in ladle treatment on the quality of continuous-cast steel pipe

The microheterogeneity of liquid and solid metal is investigated. For steel from open-hearth furnaces, the limits of carburization in ladle-furnace units ensuring the required properties of continuous-cast blank and the final pipe are determined.     

连铸大包升降油缸同步问题探讨

对连铸大包升降油缸同步的两种方案的比较,提出更适应于连铸生产环境的方案,以供共同探讨。     

Deoxidation of rimming steel in the ladle

Magnitogorsk Metallurgical Combine. Translated from Metallurg, No. 1, pp. 27, January, 1991.     

Chemical heating of steel in the ladle

Translated from Metallurg, Vol. 39, No. 12, pp. 28–29, December, 1995.     

Effect of some technical and technological parameters on the efficiency of ladle treatment of steel

The effect of the inert-gas blowing intensity, the arrangement of blowing bottom tuyeres, and the refining-slag thickness on the melt temperature during heating in a ladle-furnace unit is studied by computer simulation and upon full-scale experiments. A shift of the blowing holes from the vertical axis of the ladle and an increase in the slag thickness are found to decrease the rate of metal heating.     

Model for controlling processes in the ladle treatment of steel

In Russia, the Bardin Central Research Institute of Metallurgy (TsNIIchermet) has used results obtained from many years of basic research to construct physicochemical models of the processes of deoxidizing, desulfurizing, alloying, and finishing steel in out-of-furnace treatments in accordance with the main chemical reactions that take place. Construction of the models has in turn made it possible to develop a series of software applications designed to solve practical problems that arise in controlling the processes which occur in ladle metallurgy.     

Effective removal of nonmetallic inclusions by continuous refining of liquid steel in the intermediate ladle of the continuous-casting machine

The influence of modification of the liquid-metal flow by various structural elements (barriers, thresholds, etc.) and bottom injection on the removal of nonmetallic inclusions in the intermediate ladle of a continuous-casting machine is investigated.     

喂线技术在转炉冶炼车轴坯钢中的应用

在包钢８０ｔ转炉冶炼车轴坯钢时进行的钢包喂人Ｃａ－Ｓｉ怨芯线的工业试验表明：采用钢包喂线技术可减少夹杂物数量,并使Ａ１２Ｏ３和ＭｎＳ夹杂明显变性,因而提高了钢的质量。