Improved hot and cold rolling of steel strip

The potential for decreasing the end thickness of hot-rolled strip in traditional broad-strip rolling mills is demonstrated. The change in thickness depends on the temperature difference over the length of the hot-rolled intermediate strip. Additional reduction of the rear end of hot-rolled intermediate strip is worthwhile for other reasons. The rolling of thinner rear ends of hot-rolled strip in continuous cold-rolling mills decreases the loss of metal in end trimming.     

Thermal camber model for hot and cold rolling

The MDS profile and flatness control system is based on many physical part models. The thermal camber model is the only one of these part models which, apart from the spatial dimensions, inherently depends on the time dimension as opposed to part models like roll bending or even roll wear. This means that work roll temperature and shape keep changing even if boundary conditions like water distribution or strip contact stay constant. The exact mathematical solution of the resulting dynamic equations Is a very time consuming task usually not suitable for on-line purposes. Here a new mathematical approach is presented, which solves the 2-dimensional Fourier heat conduction equation with 3-dimensional boundary conditions at a speed suitable for on-line applications. Furthermore an approximate solution of the Hooke stress strain relations is derived, which translates the temperature distribution of the roll into an expansion distribution. This thermal camber model has been implemented in several hot and cold rolling mills. Data collected there show good agreement with the model.     

无头冷热轧生产及关键技术

总结了无头轧制技术在棒线材和带钢生产中的优势和应用发展,并对多种连接工艺进行了比较和分析,指出了无头轧制技术在今后我国钢铁生产发展中的应用前景.     

Longitudinal rolling in helicoid rollers

A new method of sheet rolling in helicoid rollers is considered. In this approach, the roller barrel is formed by a helicoid with rounded projecting tips. The effectiveness of the rollers is demonstrated, and their geometric parameters are determined. Depending on the mutual orientation of the rollers’ helical barrel surfaces, rolling will produce linear hardened zones on the strip, at some angle to its longitudinal symmetry axis. Such nonuniform deformation increases the strength of the sheet, thanks to the formation of local hardened zones, without overall loss of strip plasticity.     

宝钢四辊冷轧机轧辊次表层剥落的力学分析以及工作辊表面硬化深、支承辊重磨量的合理确定

结合宝钢２０３０五机架冷连轧机的结构和使用特点，通过对四辊轧机轧辊辊面次表层接触应力场和疲劳强度条件的分析，计算出深部接触疲劳当量应力随层深变化的结果；根据疲劳当量应力峰值所在的位置，讨论了工作辊的表面淬硬深度和支承辊重磨量大小的合理确定问题，对防止辊面早期剥落、延长其寿命，有一定的参考价值。     

Microstructure and texture evolution of Al during hot and cold rolling

The evolution of microstructure and texture of commercial purity Al during hot and cold rolling has been studied. The results show that the dynamic restoration mechanism for Al rolled to a total equivalent strain of 2.66 at a mean equivalent strain rate of 14.4 s^-1 at 510 °C is essentially dynamic recrystallization (DRX), whereas for those materials deformed to lower strains at lower strain rates at this temperature, the restoration mechanism is mainly dynamic recovery (DRV). This is confirmed by examining the microstructures, textures, and substructures of the material developed during hot rolling as well as by comparing the results with those developed during cold rolling and annealing. The texture analysis using orientation distribution functions (ODFs) indicates that the dynamically recrystallized material has a random orientation distribution, whereas dynamically recovered materials have a developed deformation texture with a predominantD component and a Cu component. The substructure observation by transmission electron microscopy (TEM) indicates that the subgrains in the dynamically recrystallized material are completely dynamically recovered, which is very similar to those subgrains in cold-rolled material. However, the annealed material shows a completely different substructure. By studying all of these structural features, which are closely associated with the dynamic restoration mechanism, it is confirmed that Al undergoes DRX in the present work, which is different from either DRV or static recrystallization (SRX).     

不同材质轧辊在型钢生产中的混合应用

Ф760mm三辊轧机各类孔型轧槽的磨损情况及轧制负荷都不相同,为了降低轧辊消耗,将不同材质轧辊如球墨铸铁辊、锻钢辊和半钢辊等在一套轧辊中进行了混合试用并获得成功,大幅降低了轧辊消耗,同时提高了产品实物质量。     

硼微合金化钢以热轧代替冷轧产品的开发

通化钢铁集团有限公司FTSR薄板坯连铸连轧生产线采用硼微合金化低碳软钢技术,严格控制钢水化学成分、成品氮含量、优化连铸和轧制工艺等,成功开发硼微合金化钢TG270,并替代低碳冷轧基料SPHC板卷,产品质量和力学性能均达到用户要求.     

Theory research on use efficiency of emulsion in cold rolling

Lubrication in cold rolling process is used not only to control friction,but also to control surface quality and thermal chamber.Successful cold rolling of strip at high speeds requires an optimum presence of lubricant film thickness at the contact.In order to have a better control on rolling process the awareness for the prediction and maintenance of desired minimum film thickness.On the basis of learning and summarizing the theories early founded by experts around the world,this paper constructed the m...     

冷热双混辊压法高炉熔渣破碎试验

围绕高炉熔渣余热回收设计开发了冷热双混辊压法高炉熔渣破碎装置,并以水淬高炉渣作为冷却介质,开展了高炉熔渣辊压破碎试验。试验研究了电机转速R、辊间距离L、冷却介质漏斗高度H等装置运行参数对处理后炉渣的厚度、温度以及玻璃化率的影响,获得最佳参数,为高炉熔渣余热回收及工业试验奠定基础。结果表明,在电机转速为9 r/min、辊间距离为2 mm、水淬渣漏斗高度为4 mm时,处理后的高炉渣呈现为厚度最小为1.26 mm的薄片。此时,炉渣温度为442 ℃,玻璃体化率达89.8%,可在保证高炉渣后续利用的同时,最大程度地提高余热回收温度。     

冷热双混辊压法高炉熔渣破碎试验

围绕高炉熔渣余热回收设计开发了冷热双混辊压法高炉熔渣破碎装置,并以水淬高炉渣作为冷却介质,开展了高炉熔渣辊压破碎试验。试验研究了电机转速R、辊间距离L、冷却介质漏斗高度H等装置运行参数对处理后炉渣的厚度、温度以及玻璃化率的影响,获得最佳参数,为高炉熔渣余热回收及工业试验奠定基础。结果表明,在电机转速为9 r/min、辊间距离为2 mm、水淬渣漏斗高度为4 mm时,处理后的高炉渣呈现为厚度最小为1.26 mm的薄片。此时,炉渣温度为442℃,玻璃体化率达89.8%,可在保证高炉渣后续利用的同时,最大程度地提高余热回收温度。     

铜钨复合材料及在热加工中的应用

铜钨复合材料是以铜，钨元素为主组成的一种两相结构假合金，以往多应用于高压电器触头等方面，近年来，增加耐磨相和添加其它元素，同时调整制造工艺，经过改性的铜钨金属复合材料，应用于热加工方面取得较好效果。     

Cold rolling with vibration of the working rollers

By means of DEFORM-2 software, cold rolling with vibration of the working rollers is simulated. It is found that self-oscillation significantly affects the fluctuation of the longitudinal stress in the metal and the rolling forces in adjacent stands of the continuous mill; and only slightly affects the longitudinal thickness variation of the strip. That leads to deviations in the surface profile.     

轧制带材的屈曲理论及其在冷轧机板形控制中的应用

本文首次应用薄板稳定理论求解了轧制带材各种复杂模态的在线屈曲临界域和瓢曲浪形成路径，成为正确的板形力学判据，它是在板形控制系统中建立控制目标设定模的理论基础，并在宝钢２０３０ｍｍ冷轧机中得以成功应用。     

热轧表面线状缺陷对冷板产品质量的影响

通过金相以及电镜、能谱分析了唐钢CSP线生产的冷轧料在热板、冷板、镀锌各工序的具体形貌以及化学成分。根据分析结果探讨了缺陷的原因，提出了相应的改进措施。     

棒材连铸小方坯冷热混装加热工艺实践

针对连铸小方坯冷热混装加热工艺 ,造成加热炉能耗及钢的氧化烧损增加问题 ,提出了在生产实践中采取的技术措施 ,以节约煤气消耗 ,减少氧化烧损 ,提高成材率。