论文

考虑剪应变对微孔洞损伤演化的影响,对GTN损伤模型的损伤演化机制进行修正,建立了适用于不同应力三轴度水平的损伤模型。结合隐式应力更新算法和显式有限元计算,采用VUMAT子程序实现了修正GTN模型在有限元软件ABAQUS中的数值计算。通过模拟纯剪切和剪切-拉伸两组试样的损伤演化和断裂行为,验证了修正GTN模型在不同应力三轴度承载条件下的有效性。运用修正GTN损伤模型模拟含边部缺口的带钢在轧制过程中裂纹的萌生和扩展行为,模拟结果与实验相一致,表明该模型可有效地用于带钢缺陷在轧制过程中扩展行为的分析和预测。模拟和实验结果表明,带钢边部缺口在轧制过程中,缺口前沿和后沿均会萌生裂纹,且后沿裂纹扩展更为明显。 Considering the effect of shear strain of micro-void on damage evolution, a modified GTN model applicable to various stress triaxiality conditions is proposed by modifying the damage evolution mechanism of the GTN damage model. The modified model is implemented in commercial finite element software ABAQUS by combining the implicit stress update method with an explicit finite element solving algorithm and through the user-defined material subroutine VUMAT. The damage evolution and the failure pro... 

6.5%(质量分数)Si高硅钢具有优异的软磁性能和广阔的应用前景,然而其室温脆性和低的热加工性极大地制约了它的发展。近年来,人们对高硅钢制备技术的研究已经取得了很大的进展,如何通过织构的优化提高高硅钢的磁性能越来越受到人们的关注,归纳和总结了不同工艺制备的高硅钢中的织构演变规律和特点,以及对应的典型磁性能。 6.5wt% Si high silicon steel has excellent soft magnetic properties and wide application prospect.However,the brittleness of room-temperature and poor workability of cold rolling limit its deve-lopment.Recently,the researches of the preparations of high silicon steel have been already made great breakthroughs,and then,more and more attentions are focused on how to optimizing the texture of high silicon steel so as to obtain the best magnetic properties.The evolution of textures of 6.5% Si high s... 

目的提高硅钢的磁性能。方法采用多弧离子镀技术,在普通取向硅钢薄板两面沉积高硅FeSi合金层制得高硅梯度硅钢,并进行热处理,观察其显微组织,测量磁性能。结果退火态高硅梯度硅钢表面的高硅FeSi合金层与基底结合紧密,均匀致密。高硅梯度硅钢中硅含量呈梯度分布,最表层硅质量分数为11.0%,随着深度增加,硅含量逐渐降低,在距表面20μm处硅质量分数仍能达到6.5%。沉积态高硅梯度硅钢的电阻率ρ、低频铁损P10/50、高频铁损P10/1k及磁感应强度B8分别为68.6μΩ·cm,0.82W/kg,83.3 W/kg和1.73 T,退火后分别为63.1μΩ·cm,0.44 W/kg,54.38 W/kg和1.89 T。结论由于表层高硅FeSi合金层的存在,梯度高硅钢的低频磁学性能良好,但高频损耗需进一步改善。 Objective To improve the magnetic properties of silicon steel. Methods FeSi alloy coatings with high-silicon content were deposited on the surface of common grain-oriented silicon steel by cathodic arc plasma evaporation,and then a kind of high silicon gradient steel was prepared. The morphologies,content and magnetic properties of the samples were tested. Results FeSi alloy coatings were featured with compact microstructures and excellent adhesive quality with the substrates. The silicon conten... 

轧制力是影响冷轧带钢厚度精度的关键因素。为实现高精度的冷轧带钢厚度控制,通过优化变形抗力模型参数和摩擦系数模型参数提高冷轧轧制力模型计算精度,并使用指数平滑法的自学习算法保证轧制力精度的稳定性。在首钢股份公司迁安钢铁公司20辊森基米尔轧机生产线进行S12硅钢钢种轧制力优化试验,将优化的模型参数应用于L2并投入现场生产,结果表明该优化方法不仅提高了轧制力设定精度,而且减小了冷轧硅钢的厚度超差长度,提高了成材率。 The rolling force is the key factor which influences the accuracy of cold-rolling strip thickness. To implement high precision control of cold-rolling strip thickness,we optimize the deformation resistance model parameters and friction coefficient model parameters to improve the calculation precision of cold-rolling force model,and use exponential smoothing self-learn algorithm to ensure the stability of rolling force accuracy. In Shougang Qiangang 20-high Sendzimir mill single stand production ...