【作者】 申娟；

【导师】 曾良才；

【作者基本信息】 武汉科技大学 ， 机械电子工程， 2008， 硕士

【摘要】 在轧钢生产过程中,板坯、方坯等在加热炉中加热都会发生氧化,并生成很厚的氧化铁皮,附着在钢铁材料表面上。另外,钢铁在轧制过程中,还会发生二次氧化,形成薄薄的二次氧化铁皮。在轧辊的辗压作用下,一部分氧化铁皮被破碎成小片状自动脱落,另一部分则被压入金属表面,形成夹渣、麻点、疤痕等,成为影响轧材表面质量的重要因素之一。为了改善成品质量,目前在钢铁轧制中广泛采用在线高压水除鳞系统。高压水除鳞系统是利用高压水喷出时产生的强大的冲刷力和冷却力,由于轧材的基体材料和氧化铁皮层的冷却收缩率不同而产生的剪切力,又因高压水水渗入基体材料和氧化铁皮之间产生的蒸汽膨胀而爆裂,使氧化铁皮破碎并与基体表面脱离,同时高压水还可将氧化铁皮冲掉。高压水除鳞系统的关键部件是高压水除鳞喷嘴。近年来,国内外一些研究人员对高压水除鳞喷嘴进行了大量的研究,结果表明,喷嘴的除鳞效果和冷却效果不仅仅与喷水条件有关,还和喷嘴的种类、结构以及安装布局有很大的关系。研制一套高压水除鳞喷嘴的性能测试系统,对国产以及进口的喷嘴进行特性测试,为生产选择合适喷嘴、提高除鳞效果和板坯质量,具有十分重要的意义。本文结合工程实际,分析了高压水除鳞系统中喷射冲击力对除鳞效果的影响,并综合研究了影响喷射冲击力的各个要素,例如喷射压力、喷嘴出流量、喷射角和喷射距离,以及喷嘴的布置对喷射特性的影响等,如喷嘴安装前倾角和偏转角,并以此设计出高压水除鳞喷嘴性能测试系统。本系统主要由三个部分组成,包括高压水除鳞喷嘴的供水系统、电气控制系统和计算机辅助测试系统。文中还讨论了喷射打击力的测试方法,提出了传感器作“之”字形运动的测试方案,并对该方案做了详细分析。本文在信号处理中,采用复合滤波技术,结合最小二乘法、曲面拟合算法,绘制了测试系统压力—流量曲线和打击力三维分布特性曲面,从而使整个测试系统控制有效,全面准确的反映高压水除鳞喷嘴的性能,对喷嘴的结构和现场安装具有重要的指导作用。更多还原

【Abstract】 During the process of heating in heating-furnace,the iron scale would be formed on the surface of steel slab and billet. Otherwise, secondary iron scale would be formed during the process of hot rolling. By the rolling of roller, a part of iron scale was broken into small pieces and fell from the plant automatically. The other part was pressed into metal surface, forming slag, bug, scars and so on. It will be one of the important factors which would impact the quality of the surface of the slab. In order to improve the quality of the product, high-pressure water descaling system was adopted widely in hot rolling mill. The iron oxide skin will broken into small fragments and disengage quickly from the surface of the plate by the powerful scouring and cooling force which was produced by the high-pressure water, and the shear force which was produced by the different cooling contractibility between steel and oxidation scale, and the expansion of the steam which was produced by the water infiltrating into the substrate and the iron scale. The iron scale will be washed out by the high-pressure water in the setting direction.In the high-pressure water descaling system, the key equipment was the nozzle. The high-pressure water descaling nozzle was studied by some technicians at home and abroad in recent years. The results showed that the effect of descaling and cooling did not only depend on the supply water, but also had a great relation to the type of the nozzles, structure and layout of the nozzles. Developing a testing system for high-pressure descaling nozzle was of great significance to choosing the suitable nozzle for plate production, improving the descaling effectiveness and the quality of slab.In this pape a research had been done on effect of the descaling by the jet impact, and studied various factors which impacted the jet such as spray pressure, flux, jet spray angle, distance and the layout of the spray nozzle. Depending on the research, the high-water descaling testing system was designed. This system mainly consisted three parts, including the water supply systems, electrical controlling system and computer-aided testing system. The paper also discussed the testing method of the jet force and the "zhi" shaped movement testing programme was proposed and done a detailed analysis.The computer-aided testing system in this paper drew the pressure-flow curve and three-dimensional distribution surface of the hitting power by the signal processed by filtering technology combined with least-squares curve, surface fitting algorithm. So that the entire testing system worked effectively and reflected the high-pressure water descaling nozzle accurately. The testing system played an important guiding role on the structure design and installation of the nozzle.更多还原