热轧带钢还原冷轧后的表面及横截面形貌

对Q215热轧带钢试样进行还原处理后,利用四辊轧机对其进行五道次冷轧试验,采用扫描电镜对还原后及不同道次冷轧后试样的表面和横截面形貌进行了观察。结果表明:还原后热轧带钢表面出现的裂纹、气泡和气孔等缺陷在冷轧过程中得到有效消除,裂纹宽度减小并趋于闭合,但五道次冷轧后,带钢表面仍然残留裂纹痕迹,且裂纹间距增大;带钢表面脱碳层厚度逐道次减小,试样表面形貌得到改善,表面质量不断提高。     

冷轧钢板表面缺陷的种类及形成原因

对冷轧钢板生产中出现的表面缺陷进行了分类,主要分析了孔洞类、氧化铁皮压入类、边裂类、起皮类等缺陷的主要待征及产生的原因;明确了相关缺陷产生的影响因素,并提出了相应的预防措施。     

润滑条件对带钢还原冷轧后表面形貌的影响

利用工业氢对热轧带钢表面氧化铁皮进行还原,随后在不同润滑条件下对该带钢进行了五道次冷轧,采用扫描电镜、粗糙度仪研究了冷轧前后试样的表面形貌和表面粗糙度。结果表明:随着轧制道次的增加,试样表面的大部分裂纹、气孔及气泡被逐渐压平,表面粗糙度降低;五道次冷轧后,干摩擦条件下试样表面缺陷的压平轧合程度最好,液压油润滑下的最差;在三种润滑条件下试样表面均有裂纹痕迹残留,液压油润滑下的裂纹痕迹最多,干摩擦条件下还存在较为明显的辊痕;干摩擦条件下试样表面粗糙度最小,为0.065μm,液压油和乳化液润滑下的表面粗糙度分别为0.089μm和0.076μm。     

冷轧板表面起皮缺陷研究

为了提高冷轧薄板的成材率,研究了冷轧薄板表面条痕缺陷的宏观和微观特征,提出夹杂物、铸坯表面裂纹、气泡是形成表面缺陷的主要原因.严格工艺操作可减少或消除缺陷.     

高强船板花斑缺陷原因分析及改进措施

针对高强船板表面出现的花斑缺陷,分析得出钢板抛丸后的红锈是造成缺陷的原因,通过调整钢板化学成分,对加热和轧制工艺采取了改进措施后,高强船板表面花斑缺陷明显减少。     

冷轧板表面缺陷成因及预防措施

对近期出现的冷轧板表面条痕状和点状缺陷进行分析，确定冷轧生产时道次轧制力不合理，原材料成分、塑性不均匀是导致产生缺陷的原因。降低轧制力、增加退火次数可减少缺陷。     

一种新型抗辊印轧辊的研制

随着对冷轧钢板表面质量要求的不断提高,一些大型冷轧厂对轧辊性能的要求也越来越高。图1为国内某大型冷轧厂1420冷连轧机组No.5机架工作辊（普通8Cr3MoV材质）辊面经常出现的辊印。轧辊辊面上的辊印缺陷传递到钢板表面,不但影响冷轧钢板质量,而且导致非计划换辊的增加,轧辊消耗增多,     

提高大型锻钢冷轧辊硬化层深度的探索

<正> 一、前言用于冷轧薄板的工作辊,常用高碳铬钢、铬钼钢或铬钼钒钢锻造制成,俗称锻钢冷轧工作辊(以下简称冷轧辊),其辊身表面要进行硬化处理,使辊身表面的硬度达到90HSD 以上,目的是为了使轧出的钢板达到规定的尺寸精度和较好的表面粗糙度。轧辊由于不断地进行轧制作业,表面磨损,形成桔皮状缺陷,需要进行修磨后再继续使用。     

热轧带钢表面缺陷在线检测的方法与工业应用

热轧带钢表面的温度高,辐射光强,并且存在着水、氧化铁皮、光照不均等现象,与冷轧带钢的表面存在着很大的差别.将线阵CCD摄像机作为图像采集装置,用绿色激光线光源作照明,通过窄带滤色镜滤除钢板表面的辐射光,从而提高了缺陷对比度.根据热轧带钢表面的特点提出新的缺陷检测与识别算法流程,通过增加4种不同类型的缺陷检测步骤,去除了大量由水、氧化铁皮等造成的伪缺陷,在保证缺陷检出率的同时,减小缺陷的误识率.经在线应用,该方法可以满足在线检测的要求,缺陷的检出率达95%以上,识别率达85%以上.     

410S酸洗板边部缺陷成因分析

针对热轧后的410S钢带酸洗时发现钢板表面靠近边部出现质量缺陷,分析确定导致此类缺陷的主要原因,为改善钢带表面质量提供工艺改进方向。     

冷轧压下率和退火工艺对St37-2G结构用冷轧钢板组织和力学性能的影响

研究了冷轧压下率和退火工艺对St37-2G结构用冷轧钢板显微组织和力学性能的影响,并优化了生产工艺。结果表明:试验钢板经不同压下率冷轧并经670℃×5h退火后的显微组织均由铁素体、少量渗碳体和微量珠光体组成,仍保留着渗碳体沿轧向呈纤维状分布的特征;随着冷轧压下率的增大,试验钢板的硬度先增大后减小,在冷轧压下率60%时达到最大值;随退火升温速率的增大,试验钢板的屈服强度、抗拉强度以及塑性应变比明显下降,伸长率和加工硬化指数变化不大;最优的冷轧和退火工艺为冷轧压下率40%～50%,退火温度670℃,升温速率20℃·h-1。     

Evaluation of Occurrence of Surface Brightness Irregularity in Cold Rolling of Stainless Steel with Emulsion

The manufacturing of stainless steel with higher brightness is improved using emulsion oil. However, in cold rolling of stainless steel with emulsion oil, it is well known that the surface brightness irregularity on the sheet surface after rolling occurs when the rolling speed is higher. It is estimated from the experimental results that the cause of the surface brightness irregularity is due to the degree of starvation in the emulsion rolling. The rolling experiments of the stainless steel with oil-in-water emulsion were carried out at various rolling speeds. The inlet oil film thickness was estimated using the evaluating system. In cold sheet rolling of stainless steel with emulsion oil, the surface brightness irregularity occurred at a rolling speed of 0.6 m/s with emulsion concentrations of 3, 5, and 10%. The experimental results showed that the surface brightness irregularity at cold coil rolling with emulsion of stainless steel occurred under a degree of starvation value of 0.16.     

轧辊表面微凸体形貌激光毛化技术的试验研究

以冷轧薄钢板冲压过程合理形貌的摩擦学设计为基础,对采用YAG脉冲激光器加工轧辊表面的微凸体形貌的机理进行了分析,并对主要加工参数的控制进行了试验研究。试验证明:激光输入功率密度在33kW/cm~2≤ρ_(S,P)≤75kW/cm~2范围内,离焦量+0.10～+0.15mm,激光扫描频率5Hz,脉宽分别为0.5ms,并采用功率增益功能,氩气保护时,可以加工出微凸体形貌。微凸体形貌制备试验的成功为进一步研究平整形貌复映关系和研究具有规则光滑凹坑表面形貌冷轧薄钢板的冲压性能提供了基础。     

冷轧薄钢板"湿法"平整的轧制压力计算

平整是使冷轧薄钢板获得合理表面形貌的关键工艺。平整轧制压力的预测与控制直接影响钢板平整后的表面质量。本文作者采用刚性、弹塑性、全滑动和边界润滑等不同模型，进行了平整轧制压力预测模型的理论分析与模拟实验研究。结果表明：当矿井下量小于5%后，轧辊的弹性变形和钢板的弹性恢复对轧制压力的影响很大，不能忽略；采用边界润滑弹塑性模型计算得到的平整轧制压力较边界润滑刚性模型更接近实验值（相对误差减小约20%）。     

冷轧硅钢产品品质对冲片性影响的研究分析

通过对冷轧硅钢片冲片加工过程及冲切模具磨损的研究分析，结合本厂实际情况，提出了如何通过改进产品品质以进一步减小模具损耗、改进冷轧硅钢冲片性的建议。     

Specimen preparation by ion beam slope cutting for characterization of ductile damage by scanning electron microscopy

To investigate ductile damage in parts made by cold sheet‐bulk metal forming a suited specimen preparation is required to observe the microstructure and defects such as voids by electron microscopy. By means of ion beam slope cutting both a targeted material removal can be applied and mechanical or thermal influences during preparation avoided. In combination with scanning electron microscopy this method allows to examine voids in the submicron range and thus to analyze early stages of ductile damage. In addition, a relief structure is formed by the selectivity of the ion bombardment, which depends on grain orientation and microstructural defects. The formation of these relief structures is studied using scanning electron microscopy and electron backscatter diffraction and the use of this side effect to interpret the microstructural mechanisms of voids formation by plastic deformation is discussed. A comprehensive investigation of the suitability of ion beam milling to analyze ductile damage is given at the examples of a ferritic deep drawing steel and a dual phase steel. Microsc. Res. Tech. 79:321–327, 2016. © 2016 Wiley Periodicals, Inc.     

Dimensional errors of rollers in the stream of variation modeling in cold roll forming process of quadrate steel tube

In the cold roll forming process, the sheet metal strip is gradually bent into a desired profile by successive roller stations. During this process the roller locating errors of each roller station are introduced, transformed and accumulated until the sheet metal is bent into the final desired profile, which does influence the product’s dimension quality, affect the end-welding of quadrate steel tube, and elongate the costly error-and-trial phase in ramp-up. This paper introduces procedures for expressing the influence of roller locating errors in the forming process of quadrate steel tube, which is based on the formulation of the stream of variation (SOV) model of roller dimensional errors using the CAD/CAPP parameters of the cold roll forming process. The SOV model is utilized to reveal the variation propagation in the manufacturing process. The modeling process is experimentally validated in a two-station forming process.     

冲压、回弹及应变速率对双相钢成形件碰撞性能影响的模拟

针对冷轧镀锌双相钢板,在完成U型梁冲压成形及回弹模拟分析的基础上,建立了闭口帽型梁的碰撞分析模型;采用映射的方法完成了U型梁的厚度、应力、应变向碰撞结构件的结果传递;在考虑冲压成形、回弹及应变速率等的情况下,对帽型梁的碰撞过程进行了模拟分析。结果表明:在碰撞过程中,由于应变速率较高,它的影响最为明显,在模型的定义过程中需要着重考虑;因为金属变形过程的加工硬化和厚度减薄等因素的影响,冲压结果直接影响碰撞过程的模拟结果;冲压后因回弹使零件内部的应力得到释放,残余应力减小,因此导致碰撞过程中产生相同的变形需要更大的外力,考虑回弹的刚性墙反力要比没有考虑时的高。     

镍铝青铜焊丝进行镁/镀锌钢板点焊的焊接性分析

以镍铝青铜焊丝为填充材料,对AZ31B镁合金/镀锌钢板进行冷金属过渡点塞焊试验研究,分析镁板上孔直径对镁钢点塞焊接头力学性能的影响.并通过分析焊接接头微观组织及其元素分布状况来研究其连接机理。研究结果表明:使用镍铝青铜焊丝能够得到焊缝美观的镁/镀锌钢异种金属的连接接头。镁/钢板焊接接头的焊缝主要由a-Cu和Cu Al_2组成,熔合区由镁的固溶体a-Mg以及Al_2Cu_3Mg_2和Mg_2Cu混合的金属间化合物组成。镁板上孔的直径对镁钢接头性能有很大的影响。随着镁板孔径的增大,镁钢点塞焊接头的最大抗拉载荷先增大后减小,且当镁板孔径为5 mm时接头的最大抗拉载荷达到最大为3.4 k N。焊缝金属和镁母材的连接处即熔合区存在大量脆性金属间化合物,使得镁/钢接头整体力学性能较差。     

Evaluation of boundary lubrication characteristics by sem

The boundary lubrication characteristics of three lubricants used in the cold rolling of steel were evaluated on a disc machine using EN31 and mild steel as the disc pair materials. The surfaces, subject to superficial deformation, and the wear particles were examined by scanning electron microscopy (sem). The behaviour of the three lubricants could be clearly differentiated. This method, although not a precise representation of the process, could be used to evaluate the boundary lubrication characteristics of steel cold rolling oils