共查询到19条相似文献,搜索用时 203 毫秒
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对多辊型钢矫直机实测扭矩值进行了分析;探讨了负扭矩的形成原因及其后果,提出扭矩干涉产生的负扭片面矩是造成传动轴超负荷的主要原因。提出了合理配辊与三辊从动的矫直工艺。该工艺在攀钢实施的结果,可有效地降低传动轴扭矩和矫直噪音。 相似文献
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介绍了宣钢连轧中型生产线KXJ800矫直机在生产中存在的弯曲、尺寸超差、磨损、扭转、波浪湾等产品缺陷。通过分析论证,用KXJ900矫直机取代KXJ800矫直机后,增强了喷水系统的冷却能力、改进了矫直辊顶角、降低了矫直辊硬度6HSD,大大减小了角钢弯曲度,解决了矫直后的轧件变形问题。 相似文献
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通过理论分析计算和现场测试,证明轧件在矫正过程中,由于轧件受不同的弯曲变形,中性层会产生前进速度差,从而引起负扭矩,出现打滑现象,继而产生振动和噪音。 相似文献
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重轨矫直过程是一个变变的弹塑性过程,在矫直力的作用下,轧件断面发生变形。分析及研究轧件在矫直过程中变形机理,首先必须了解被矫直材料变表时的机械力学性能,通过材料拉伸实验,利用数学分析方法,得出重轨材料在弹性变形、塑性变形时应力应变关系的精确的数学模型,准确反映材料一次弯曲变形时的机械性能。重轨同是非对称断面,本文对中性层的偏移进行了定性,定量的分析。 相似文献
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分析了典型中型窄翼缘H型钢生产工艺中的难题及限制经济技术指标提升的原因。通过采取粗轧孔型系统的优化、激光合金熔覆技术的应用、优化精轧机组压下量分配、离线工装精度的提高、矫直精整工序设备精度的恢复及适应性改造等措施,解决了窄翼缘H型钢腹板波浪与翼缘尺寸难以控制的问题。提升了该类H型钢成材率。 相似文献
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H型钢辊式矫直过程及矫直后的残余应力对其承载能力有很大影响,传统上以残余几何形态评价矫直效果存在一定不足.基于弹塑性理论,对辊式矫直过程中H型钢断面上弹性核高度和残余应力进行了理论研究,推导出了相关解析公式,结合实例计算及仿真,验证了解析公式的正确性,对现场工艺参数的制定提供了理论依据. 相似文献
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运用有限元方法对H型钢万能轧制过程水平辊温度场进行了数值模拟,根据模拟结果分析了水平辊辊面温度分布状况,结果表明:与H型钢腹板部位接触的水平辊辊面温度较低,与H型钢R角部位接触的水平辊辊面温度最高。此外,还完成了小型H型钢万能轧机水平辊冷却试验,水平辊冷却方式分别为气雾冷却和水冷,试验结果表明:轧辊采用气雾冷却方式进行冷却时,型钢腹板残留冷却水较少且型钢表面温差较小,轧辊辊面温差和轧辊磨损程度均较小,且轧后轧辊温度更容易降至室温。总体而言,轧辊采用气雾冷却效果比采用水冷效果好。 相似文献
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V. N. Shinkin 《Steel in Translation》2017,47(10):639-644
In the straightening of steel sheet, it is necessary to calculate the optimal reduction of the steel blank by the working rollers of the straightening machine so that the sheet produced has the minimum residual stress and curvature. In the simulation of sheet straightening in multiroller machines, the curvature and bending torques of the steel sheet at contact points with the working rollers are first calculated and then the straightening forces are determined. In straightening steel sheet, it is important to calculate the forces in the multiroller straightening machine. Such calculations are based on determination of the reaction of the roller bearings and the forces at the upper and lower working-roller cassettes in straightening. With insufficient bending torque, it is impossible to eliminate harmful residual stress and surface defects in the sheet. Extreme roller torques and forces at the roller cassettes often lead to defects of the sheet, fracture of the working and supporting rollers, and failure of the straightening machine. In the present work, an approximate method is proposed for calculation of the optimal cold-straightening parameters of the steel sheet in a multiroller machine. The calculations permit determination of the curvature of the neutral plane in the sheet on straightening, the residual curvature of the sheet after straightening, the bending torque and the reaction of the working-roller bearings, the residual stress in the sheet, the penetration of the plastic deformation into the depth of the steel sheet, and the relative deformation of the longitudinal surface fibers of the sheet on straightening as a function of the radius of the working rollers, the distance between the rollers of the straightening machine, the reduction of the sheet by the upper rollers, the sheet thickness, and its properties (Young’s modulus, yield point, and strengthening modulus). The results may be widely used at manufacturing and metallurgical plants. 相似文献
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摘要:以管材六斜辊矫直过程为研究对象,推导了管材经一次反弯后,弹复曲率及残余曲率的演变过程。根据管材旋转一圈弯曲2次,计算了管材全流程矫直微元段的反弯次数;借助三次样条函数,以管材与矫直辊接触点为特征点,拟合出了管材在辊系中的弯曲形态。基于所获得的函数,可以获得任意位置处的弯曲曲率;对某一微梁段的反弯弹复过程进行循环迭代,计算出管材微梁段的最终残余曲率,进而得到最终的管材矫后的直线度精度。通过与现场矫直数据对比,证明该模型能够可靠地预测六斜辊矫直精度,为科学合理的设定矫直参数奠定了理论基础。 相似文献
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The capture conditions for an H-beam blank by the grooved rollers in the 1300 reduction stand of a universal beam mill at Nizhny Tagil metallurgical works are considered. The stress–strain state of the metal in the deformation regions on rolling the beam in the roller grooves of the reduction stand is investigated. The calculation results are presented as the distribution of the contact normal and tangential stress in the deformation regions as the H-beam blank is captured by the rollers. The normal tensile stress in the wall of the Hbeam blank is no more than 52 MPa. In the deformation regions of the crosspieces and at their junction with the wall, the normal contact stress is compressive. That indicates a stress state favorable in terms of H-beam quality, with high compressive stress. A method is developed for calculating the dynamic loads in the drive line of the 1300 reduction stand, with allowance for the gaps in the spindle joints. 相似文献