铸轧-冷轧铝板退火产生气泡的机制

根据铝铸轧生产的特点和气体在铝熔体中的溶解与析出行为,通过图示法分析了铸轧铝板坯经冷轧、退火后产生气泡缺陷的原因。总结了铸轧工艺参数对铸轧铝板内气泡运动行为的影响。     

主应力法计算蛇形轧制的轧制力

使用主应力法建立蛇形轧制过程中轧制力与轧制力矩的解析预测模型。将解析模型的计算结果与实验结果进行比较,验证了解析模型的准确性。运用该模型对蛇形轧制过程中不同的异速比、轧辊偏移距离、压下量和摩擦系数对轧制力和轧制力矩的影响规律进行研究。同时研究"搓轧区"对轧制力和轧制力矩的影响。结果表明,异速比的增大将导致"搓轧区"的增大,从而使轧制力和上轧辊轧制力矩减小,下轧辊轧制力矩增加。当异速比增大到速度较大的轧辊带动速度较小的轧辊时,慢速轧辊的轧制力矩将变为负值。轧辊错位距离的增大导致"搓轧区"减小,从而导致轧制力增加,上、下轧辊轧制力矩减小。压下量的增加导致"搓轧区"的减小,从而导致轧制力和上、下轧辊轧制力矩的增加。轧辊与轧板之间摩擦系数的增加使"搓轧区"减小,同时导致轧制力和上、下轧辊轧制力矩同时减小。研究为蛇形轧制在超大厚度板材制造中的应用,提供了理论基础。     

冷轧薄板表面色差原因分析

利用共聚焦显微镜对冷轧薄板的色差表面形貌进行观察,发现条状色差主要是由于带钢表面粗糙度不均匀引起。通过生产现场调研发现,在焊缝连接处色差纹路具有连续性特征,且通过轧机急停取样后发现色差主要是由于连轧机的5#机架引起。分析表明,带钢粗糙度不均与轧制过程中乳化液油膜在工作辊面分布不均相关,而油膜不均与乳化液的喷射方式、轧制速度、乳化液的颗粒度和接触角存在直接关系。通过增加乳化液辅助喷嘴,控制轧制速度,并将轧制油的颗粒度由13μm降低至8μm,油滴接触角由80°降低至63°,色差缺陷得到解决。     

Stress analysis of asymmetrical cold rolling of clad sheet using the slab method

An analytical model for general asymmetrical cold rolling of clad sheet bonded before rolling was proposed to explore the plastic deformation behavior of the clad sheet using the slab method. The model allowed easy calculation of the neutral points between the upper and lower rolls and the clad sheet; rolling pressure distribution along the contact interface of the roll, horizontal stresses in the component layers of the clad sheet, shear stresses at the interface of the clad sheet, and rolling force. These characteristics as affected by various rolling conditions (e.g., thickness ratio and shear yield stress ratio of the raw clad sheet, roll speed ratio, reduction, frictional coefficient, roll radius ratio, etc.) were analyzed systematically. This approach yielded complete forms for the rolling pressure distribution, rolling force, and rolling torque. Moreover, the computational time required by this analytical model is about 1/20 to 1/25 of that required by the RUNGE KUTTA numerical method under the same rolling conditions.     

热轧薄规格集装箱钢板的大张力轧制

在找出带钢在热连轧精轧机组中产生跑偏、卡钢和轧破等原因的基础上,提出热轧薄规格集装箱钢板大张力轧制工艺,并对其科学性、可行性进行了分析;同时介绍了采用大张力轧制工艺取得的良好效果。     

SS330、SS400连铸连轧板卷通条力学性能探讨

通过对SS330、SS400连铸连轧板卷通条力学性能和检验试样代表性的研究,得出唐钢薄板坯连铸连轧控冷工艺制度合理,热轧板带钢通条力学性能、金相组织均匀。距成品带钢尾端4m处试样的性能对整个板卷的性能具有很好的代表性。     

铝合金板成形中摩擦与润滑的研究进展

概述了铝合金板成形过程中的摩擦机理、摩擦模型和润滑的发展现状.全面分析了铝合金板成形的影响因素,阐述了润滑剂的作用机理,展望了其发展趋势,提出铝合金成形应走环保型"绿色"润滑之路.     

Analysis of asymmetrical hot strip rolling by the slab method

Two analytical models based on the slab method are proposed to examine the behavior of sheet at the roll gap during the asymmetrical hot strip rolling process. In model I, the effect of shear stress in vertical plane at the roll gap is considered, whereas this effect is neglected in model II. Neutral points between rolls and strip, rolling pressure distributions along the contact art length of rolls, rolling forces, and rolling torques can be calculated easily by these proposed analytical models. The results including rolling pressure distributions, rolling forces, and rolling torques by both models are compared. The rolling pressure distribution predicted by model I shows that a “pressure well” develops in the cross shear region. On the other hand, no “pressure well” is predicted in model II. Furthermore, the rolling forces predicted by model I are always lower than those measured in the experiment, whereas those predicted by model II are always higher. However, the averages of the values predicted by model I and II are in fairly good agreement with the experimental data. Thus this analytical approach can offer useful knowledge in designing the pass schedules of the asymmetrical hot strip rolling processes.     

热轧润滑的效果——热轧润滑技术讲座（二）

介绍了热轧润滑技术在国内外热连轧机上的应用效果,即可明显减少辊耗,降低轧制力,轧制力矩,提高作业率,因而经济效益非常明显;同时提出进一步改善热轧润滑效果需要重视的问题。     

Mg-Zn-Y-Zr合金轧制板材的热处理

对真空熔炼的Mg-Zn-Y-Zr合金在380℃下进行热挤压,随后取部分挤压棒在400℃下轧制成厚度为3 mm的薄板,再进行不同工艺的固溶时效处理。薄板的最佳热处理工艺为530℃×4 h+200℃×8 h。分别对热处理前后薄板试样的显微组织和力学性能进行分析和测试。结果表明,经过固溶时效处理后薄板的抗拉强度显著提高,达到356 MPa,而伸长率有所下降。     

薄带冷轧接触力学(英文)

极薄带冷轧给轧制生产带来了挑战,其中包括接触力学、带材的凸度和表面质量。在考虑工作辊边部接触的前提下,采用自行开发的改良影响函数法对薄带的对称和非对称冷轧过程进行了分析。文章的重点是通过薄带冷轧来阐述辊缝接触力学,分析辊缝处的摩擦对轧制力学和带材凸度的影响,同时还对轧辊边部接触对轧制力学和带材凸度影响进行了讨论,认为轧辊边部接触将对工作辊边部磨损产生影响,并对轧制力计算值与实测值进行了比较。     

SiC颗粒增强铝基复合材料薄板轧制工艺研究

研究了轧制方式、轧制温度等对SiC颗粒增强铝基复合材料显微组织和力学性能的影响.轧制温度为410℃,沿平行于挤压方向进行交叉轧制可以制备出高质量、高性能的薄板.轧制态7075/SiCp复合材料薄板的力学性能为: δa=542.51 MPa, δb=666.09 MPa, δ=4.91%.轧制变形对挤压过程中形成的SiC颗粒条带状不均匀分布也具有改善的作用:轧制过程中,SiC颗粒破碎,尺寸明显变小,形貌呈钝化趋势,随着轧制变形量的增加,SiC颗粒分布趋于均匀.     

热轧和冷轧工艺对MGH754合金板材组织及性能的影响

通过光学显微镜、扫描电镜和透射电镜对热轧和冷轧后的MGH754合金板材的显微组织和断口形貌进行了分析,研究了冷轧与热轧工艺对其组织以及力学性能的影响。结果表明,MGH754合金热轧板材的终态组织是发生了二次再结晶的粗晶组织,而冷轧板材只发生了一次再结晶。热轧板材的高温抗拉强度要优于冷轧板材,但其高温伸长率却低于冷轧板材。     

Slab analysis of asymmetrical sheet rolling

In this paper, a theoretical model based on slab method of analysis for plane strain asymmetrical rolling is presented. In this model the non-uniformity of the normal and shear stresses in deriving of the governing equations are considered. This model can predict the required external loading to the plate at entry to keep the plate horizontal. The analytical rolling force, torque and pressure of this model were compared with the experimental and analytical results of other investigators. Numerical and experimental results are shown to be in good agreements.     

An analytical approach to asymmetrical cold strip rolling using the slab method

An analytical model for general asymmetrical cold rolling is proposed to investigate the behavior of sheet during asymmetrical rolling using the slab analysis. Neutral points between the upper and lower rolls and the strip, rolling pressure distribution along the contact interface of the roll and strip, and rolling forces, as well as rolling torque, can be calculated easily using this model. Rolling pressure distribution, rolling force, and rolling torque, which are affected by various rolling conditions such as roll speed ratio, thick-ness reduction, front and back tension, etc., are analyzed. Additionally, the limiting rolling conditions be-tween reduction and roll speed ratio, or front and back tension, under which the rolling process can be accomplished successfully, are discussed. By comparing analytical results and experimental measure-ments of rolling force, it is apparent that the proposed model can successfully provide useful knowledge for designing the pass schedule of the asymmetrical cold strip rolling process.     

酸洗冷轧过程中轧件表面形貌演变规律研究

利用四辊轧机对酸洗后带钢进行了冷轧实验, 采用扫描电子显微镜对试样冷轧前后的表面形貌进行了跟踪观察, 采用TR200型粗糙度测量仪测试了轧制前后试样的表面粗糙度轮廓曲线, 研究了不同轧辊表面状态和摩擦条件下冷轧带钢表面形貌的演变规律。结果表明: 轧件表面形貌主要取决于表面凹坑和辊痕的尺寸, 随轧辊表面粗糙度的减小和轧制道次的增加, 轧件与轧辊表面的实际接触面积增加, 轧件表面凹坑和辊痕的尺寸均减小, 轧件表面光洁度提高; 当轧辊辊面粗糙度相同时, 采用油润滑轧制的试样表面光洁度比干摩擦轧制的试样表面光洁度高; 冷轧前几个道次轧辊的表面状态对最终成品带钢的表面形貌同样起着重要作用。     

温轧AZ31镁合金薄板的快速退火处理

对1 mm厚温轧AZ31镁合金薄板进行快速退火处理,退火温度350～500 ℃,保温时间0.5～60 min,研究了不同快速退火工艺下材料力学性能与微观组织的变化。结果表明：在退火温度为350～500 ℃时,保温时间为0.5～1 min即可使材料的伸长率大幅提高;在退火过程中,材料经亚动态再结晶、静态再结晶和长大3个阶段,其中亚动态再结晶阶段时间较短,约0.5～1 min,此阶段对材料力学性能的变化起主要影响。     

热轧润滑油中的添加剂及热轧润滑在我国的发展——热轧润滑技术讲座(四)

介绍了热轧润滑油中各种添加剂的成分和功能，以及对其性能的要求，同时分析了热轧润滑在中国的发展前景。     

用KH计算法模拟铝板带冷轧压下规程

分析了冷轧铝板带压下规程的特点,提供了快捷模拟大厂现行冷轧压下规程的步骤,为进一步创新和优化冷轧压下规程创造条件,为工厂节能和增产创造条件。     

Influence of rolling ways on microstructure and anisotropy of AZ31 alloy sheet

Two rolling ways,unidirectional rolling and cross rolling,were carried out on twin roll cast AZ31 alloy sheet to study the influence of strain path change on the evolution of the rolling microstructure and texture as well as the anisotropic properties of AZ31 alloy sheet with microscopy,X-ray diffraction technique and tensile tests.It is found that cross rolling gives rise to more uniform microstructure and stronger texture intensities compared with unidirectional rolling.The differences in the microstructure and texture intensities are reflected in the anisotropy characterized by the difference in the yield stress and the fracture elongation that were measured along directions in the rolling plane at angles of 0■,45■and 90■from the rolling direction.