冷轧过程轧板内圆形夹杂物变形

运用ANSYS/LS-DYNA显示动力学有限元软件,建立了水平辊系二维五连轧弹塑性有限元模型,利用小型重启动方法对DCO3冷轧板五连轧过程中轧板内硬性夹杂物变形进行了模拟,分析了夹杂物尺寸、初始位置以及轧板压下量对夹杂物变形的影响。研究结果表明：模拟结果与实际相接近,轧板内夹杂物的变形程度主要随着轧板压下量的增加和夹杂物尺寸的增大以及夹杂物距轧件表面距离的减小而增大。轧件由3.0mm被轧到0.7mm,夹杂物直径超过20μm时,轧制结束后夹杂物前后部位处变形程度较大,轧件内部可能会产生由于夹杂物破裂而形成的裂纹源。     

Machine Learning Model for Thickness Evolution of Oxide Scale During Hot Strip Rolling of Steels

Metallurgical and Materials Transactions A - Oxide scales have significant influences on the surface qualities of hot-rolled steels. In the present work, an oxidation kinetic model for anisothermal...     

微合金钢超细组织的控制轧制

探讨了采用应变诱导轧制及应变诱导轧制与常规控轧技术相结合获得超细晶铁素体组织的可行性,研究了冷却速度对应变诱导铁素体晶粒长大的影响,实验结果表明,采用应变诱导轧制可显细化铁素体组织,将应变诱导轧制技术与常规控轧工艺相结合所获得的超细晶组织更为理想。通过实验室模拟轧制,已获得体积分数为９７％、晶粒尺寸达０．９２μｍ的超细铁素体组织,ＴＥＭ分析发现,超细晶铁素体内位错密度较低并有少量小角度晶界存在。     

轧花铝板二辊冷轧机的设计与研究

本文给出了二辊冷轧机轧制H=0.5mm,B=400mm,△h=0.008mm轧花铝板的主要参数(轧制力,轧制力矩,弯曲刚度)。讨论了主要零件的加工精度(轧辊、机架)和二辊冷轧机的结构。     

钢材性能柔性化与柔性轧制技术

为解决用户个性化需求与企业规模化生产之间的矛盾,提出将组织性能在线优化控制技术应用于柔性轧制,用同一种成分的坯料来生产不同性能的产品,简化炼钢和连铸的操作和管理,利用对钢材性能柔性的控制实现轧制生产的大规模定制.指出当前2种可行的柔性轧制实例:用普碳钢生产屈服强度为200～400 MPa的产品,用碳锰钢生产屈服强度为350～600 MPa的产品.     

Microstructure and Texture Evolution During Hot-Pack Rolling of Nickel-Base Superalloys to Thin Sheet and Foil

Microstructure evolution during hot-pack rolling of nickel-base superalloys to ~1-mm-thick sheet and ~200-μm-thick foil was investigated with electron backscatter diffraction. The microstructure was observed at increasing levels of strain, which revealed the progressive formation of an unrecrystallized, banded microstructure at sheet gage. The bands contained large orientation gradients, sometimes spanning multiple texture components considered to be stable with respect to the imposed plane-strain compression. After reaching stable orientations, grain-scale shear bands were observed within individual unrecrystallized bands that resulted in local subgrain rotations that formed new bands of different orientation. This phenomenon, which is known as band splitting in the literature, was shown to be the result of continuous dynamic recrystallization as opposed to discontinuous dynamic recrystallization or classical static recrystallization. The unrecrystallized bands were eliminated by unidirectional rolling to foil but not by cross rolling.     

发动机用减振钢板的冷冲压工艺

减振钢板是由钢板/树脂/钢板组成的复合钢板,表面厚度通常为0.3～1.6 mm,中间高分子树脂采用0.03～0.15 mm,厚度没有严格限制.     

轧制法生产始极片的工艺及应用

介绍了轧制法生产始极片的新工艺——MKM公司铜板带连铸连轧工艺。与传统钛种板生产始极片相比，轧制法生产的始极片，由于其表面提高了几何准确性，减少了电极间距，增大电流密度，取消了制造始极片所需的电解槽，因而大大提高了电解车间的生产能力。     

Hidden Potential of Cold Sheet Rolling

Metallurgist - Symmetric rolling (SR) where the roll speeds are equal and rolling-drawing (RD) where the roll speed ratio is limiting are versions of general rolling (GR). An advantage of GR is in...     

谈微合金化钢的控轧控冷技术

通过查阅大量参考文献,主要综述了控轧控冷技术的原理、特点及控制要素,并分析了控轧控冷对微合金钢的组织与性能的影响。     

用高精度组织控制技术生产成型性优良的汽车钢板

日本川崎钢铁公司在汽车用钢板的开发过程中，始终将提高高强度钢板的成型性等各种性能作为开发目标。代表性的例子就是开发出喷漆烘烤后屈服强度和抗拉强度都提高的BHT钢板和通过动态再结晶细化晶粒提高拉伸性能和扩孔性的超HSLA钢板。这两种钢板都是以1995年投产的千叶厂第三热轧车间的新技术为基础，利用全新的金属学原理对钢组织进行高精度控制开发出的产品。     

宝钢镀锌钢板的发展

随着国内经济的持续稳定发展,在过去的10年中,由于建筑和汽车行业的快速发展,对镀锌钢板的需求持续旺盛.在今明两年,国内宽带钢连续镀锌钢板生产线的发展将进入高峰期,每年的新增产能近1 000万t.简要回顾了国内镀锌钢板的发展和消费结构,并对下一步镀锌钢板的发展进行了展望.此外,结合宝钢镀锌生产线的建设,简要介绍了宝钢主要的镀锌钢板新品种开发情况.     

Measurement of Banded Microstructure Characteristics in Sheet Steels

Metallurgist - The article discusses factors determining the reproducibility of measurement results for a banded microstructure in sheet steels St3sp and 09G2s using computerized procedures.     

Annealing Response of Cold-Rolled Vanadium Microalloyed Sheet Steels

Vanadium microalloying is widely employed in hot-rolled HSLA products;because of its relatively high solubility in austenite,vanadium plays a special role in thin-slab cast hot-rolled products where reheating is limited prior to direct-rolling.In cold-rolled and annealed sheet steels,vanadium technology has been employed in bake-hardenable drawing-quality steels,and in HSLA products.Recent studies have investigated the continuous and batch annealing response of vanadium-containing cold-rolled HSLA steels,with an emphasis on aluminum and nitrogen variations (because of the special importance of nitrogen in vanadium microallyed steels,and interesting interactions between vanadium,aluminum and nitrogen).The present contribution reviews some key aspects of vanadium-microalloyed coldrolled sheet steels,and highlights the results of selected studies showing the influence of steel composition and processing.     

Structure and Texture Formation During Single and Double Cold Rolling and Annealing Processes for Nb+Ti Added Interstitial-Free Steels

 The structure and texture formation for single cold rolling (SCR) with annealing and double cold rolling (DCR) with annealing were investigated based on optical microscope and X-ray diffraction (XRD) with a Nb+Ti bearing interstitial free (IF) steel. The results indicated that DCR recrystallization grain was smaller than that of SCR sample and double cold rolling process resulted in better mechanical properties than those resulted from single cold rolling process with the same total reduction conducted. The plastic strain ratio increases from 2. 23 for single cold rolling process to 3. 2 for double rolling process. The fish-bone structure was observed in all SCR and DCR samples. DCR annealed sample is made up of equiaxed grains of almost uniform size, whereas SCR annealed sample shows a duplex grain structure, consisting of both large and small-sized grains. (Ti+Nb)C and Fe(Ti+Nb)P type precipitates were very rarely observed in SCR annealed and DCR annealed steels. The intensity of {111}∥ND for the DCR annealing was higher than that for SCR annealing.     

减振复合板试制应用

减振复合板是通过一层30~80 um厚的高分子阻尼材料将两张钢板粘结复合在一起,使其既具有高分子阻尼材料良好的减振、降噪效果,又具有金属材料良好的加工成型性的功能型复合材料,是振动和噪音场所替代纯金属材料理想的环保产品。简述了减振复合板国内外发展状况,通过试制及实际应用,表明减振复合板减振、降噪效果良好,在家电、汽车、建筑等行业应用前景广阔,是21世纪新材料发展的方向。     

中厚板轧制过程中的轧制力和轧制力矩数学模型

本文提出了两个新的无量纲参数轧制力功系数和轧制力矩功系数,并通过对这两个参数的回归分析,建立了高精度的轧制压力和轧制力矩数学模型。     

薄板冷连轧机组轴承烧损的故障诊断

薄板冷连轧机组轴承烧损事故逐渐增多,造成经常停机更换圆锥滚子轴承。根据故障产生的特点,轴承烧损大多集中在轧制功率高的轧辊上。现场发现由于存在过大的轴向力,使得载荷集中到2列甚至1列轴承上。测量数据分析发现轧制时的轴向力随着轧机牌坊的磨损程度——轧辊与轧制中心线的倾斜程度加大。通过更换轧机牌坊的衬板,修复牌坊的几何尺寸,更换轧辊轴承箱的衬板,修复轧辊轴承箱的几何尺寸,使轧辊轴承的烧损下降到过去水准的三分之一以下,保证薄板冷连轧机组安全运行。     

A Simple Model for Conventional Hot Rolling of Sheet Materials

Temperature transients during the bare hot rolling of sheet materials have been modeled using a simple one-dimensional, finite-difference heat-transfer approach. The model addresses heat losses associated with (1) the transfer of the sheet from the reheat furnace to the rolling mill and (2) the actual rolling operation itself. The former step comprises heat losses primarily through radiation and the latter through chilling of the hot workpiece in contact with the cooler rolls. The principal output of the model is the temperature field through the thickness of the sheet. The usefulness of the model was gaged through an investigation of the effect of temperature transients on the hot-rolling behavior of Ti-6Al-4V sheet. Specifically, the effect of temperature transients on rolling pressure and development of nonuniform microstructure was determined. Over the entire temperature range studied, the rolling pressure for Ti-6Al-4V was found to be dependent only on the average temperature of the workpiece within the roll gap, irrespective of metastable phase transformations that may have accompanied the deformation process itself. The one-dimensional heat-transfer model was also successful in explaining the occurrence of the nonuniform microstructures produced during rolling at nominal (furnace) temperatures near the beta transus.