共查询到19条相似文献,搜索用时 46 毫秒
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针对攀钢连退机组因采用干平整工艺而易造成冷轧产品表面平整辊印和平整色差的问题,开展了湿平整工艺的技术研究。通过对平整机入口喷射梁、出口压缩空气吹扫装置和热风烘干装置的改造和优化,以及对湿平整各工艺参数的研究,使平整辊使用寿命显著提高,非计划换辊次数平均每天降低2.8 次或93%,产品表面质量显著提高,I组品率提高了38个百分点,降组率减少了16个百分点。 相似文献
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阐述了抗时效镀锡产品的几种连续退火生产工艺,通过采用连续退火R-OA、无间隙原子化处理以及材料晶粒尺寸控制的方法之一可以有效地减缓或消除材料时效的发生,从而可能避免材料的起棱或滑移线现象的产生。 相似文献
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针对新余钢铁集团有限公司连退线存在的炉内张力控制难度大、薄规格带钢的高速运行不稳定等问题,分析了连退线在生产薄规格带钢时炉内张力波动,适应性差和相邻道次张力差增大的原因,提出并运用了减小炉内张力波动、优化张力调节器限幅控制、优化炉辊负荷平衡控制、优化张力检测等张力控制优化方案,尤其是与速度成比例的张力调节器限幅控制方案。通过优化方案的实施,提高了不同炉况炉内张力与带钢速度和温度的适应性,减小了对张力设定值适应性的要求,同时炉辊与带钢的打滑及带钢跑偏问题得到了明显改善,薄规格带钢在炉内可以300 m/min以上的速度稳定运行。 相似文献
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以金红石型铬镍奥氏体不锈钢焊条焊缝为研究对象,以气泡浮出速度理论为基础,综合介绍了不锈钢焊缝中气孔形成机理研究的几种观点:药皮中水分影响理论、熔滴中非金属夹杂物影响理论、焊缝金属凝固模式影响理论和熔滴过渡形态影响理论,为后续研究及工程应用提供了必要的理论依据。 相似文献
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冷轧平整横折印缺陷产生原因和消除方法 总被引:4,自引:0,他引:4
针对冷轧平整存在横折印问题进行了分析 ,找出其产生原因及消除方法 ,并研制了带V型槽和凸度的张紧辊。新张紧辊对减少横折印缺陷效果明显 ,缺陷数量可减少 99 2 %以上。 相似文献
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研究了连续退火均热段温度和平整工艺对冷轧超低碳BH钢的组织和力学性能的影响规律。结果表明,超低碳BH钢在740~850℃之间均能完成再结晶退火,且随着均热段温度的升高,BH钢的屈服强度和抗拉强度单调下降,n值单调上升;伸长率和r值先上升后下降,并同在820℃左右达到峰值;显微硬度也呈单调下降趋势。平整伸长率由0向1.8%增加过程中,钢板的强度呈下抛物线形变化;低于0.8%时会产生屈服平台;高于1.5%时,加工硬化加剧导致强度快速上升,屈服强度可在1.2%~1.5%之间达到最低值。 相似文献
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Thick oxide scale on steel may result in serious surface defects on hot-worked products. Yield efficiency and productivity of processes are considerably deteriorated by formation of defects. It is highly demanded to establish a way to produce hot-worked steels free from surface defects by controlling oxide scale. The oxide scale shows various behaviors in hot rolling; (a) uniform deformation with matrix steel, (b) cracking, (c) fragmentation, (d) indentation to matrix steel, etc. Through observations using glass coating, it is found that the behavior strongly depends on the rolling temperature as well as the scale thickness before rolling. Temperature drop due to contact with cold rolls is found to cause the cracking and a major reason for the thickness dependence. It is found that the scale cracking is predictable using the estimated scale temperature and the ductile-brittle transition temperature of Wustite (FeO). Then, methodology to produce hot rolled steels without surface defects in industrial processes is presented. 相似文献
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以DEFORM-3D软件为基础, 分析了中厚板轧制过程中材料的横向流动规律及代表性的轧件端部曲线方程。以端部缺陷代表性的曲线方程为基础, 构建了MAS轧制过程控制参数的在线设定模型。实验表明: 该MAS轧制过程设定模型可以较大幅度地减小端部量, 提高成材率。 相似文献
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J.H. Min H.C. Kwon Y. Lee J.S. Woo Y.T. Im 《Journal of Materials Processing Technology》2003,140(1-3):471-477
In process design of bar rolling, accurate prediction of deformed shape of the rolled workpiece is important in determining the total number of passes. Thus, development of an approximate analytical model for predicting an accurate rolled shape with less computation time will be beneficial for practical purpose. In the present study, such a model for the three-roll system with multi-passes was developed by deriving spread and geometrical configuration formulae from the finite element (FE) analysis results of a seven-passes sequence rolling. In FE simulations, process parameters such as the initial workpiece geometry and the amount of roll draft and roll speed were varied. By comparing spread ratios of FE simulation results three representative geometry changes (round–curved hexagonal, curved hexagonal–hexagonal, and hexagonal–hexagonal) were identified. For each representative geometry change those two formulae were determined in the present investigation. The formulae determined were further applied to a three-roll process with four-passes sequence. The final workpiece geometry predicted based on the model developed was found to be in good agreement with experimental and FE simulation results. Thus, the analytical model developed in the current approach can be effectively used in the design of multi-pass three-roll rolling processes. 相似文献