钢厂
凝固速率对定向凝固50W600无取向硅钢固液界面稳定性和枝晶间距的影响
采用ZMLMC超高梯度定向凝固装置,研究了5种凝固速率(10、35、80、150和450μm/s)对定向凝固50W600无取向硅钢的固液界面稳定性转变规律和一次、二次枝晶间距的影响。研究结果表明,在特定的温度梯度下,随着凝固速率的增加,定向凝固的固液界面由胞状晶转变为胞状枝晶,再转变为细小的树枝晶。随着凝固速率的增加,定向凝固组织的枝晶形貌逐渐细化,一次和二次枝晶间距逐渐减小,且与冷却速率之间都符合指数关系:λ1=151.73×(G L·R)-0.31,λ2=22.07×(G L·R)-0.44。当冷却速率达到4.275℃/s时,一次、二次枝晶间距分别为112μm、14.1μm。 Under the conditions of certain temperature gradient and different solidification rate,the directional solidification experiment of non-oriented electrical steel 50W600 was carried out.The microstructure of 50W600 steel was also analyzed in different solidification rate.The result shows that the solid/liquid interface of the steel undergoes an evolution from cellular,cellular dendrite and finally to fine dendrite morphologies.The dendrite refines gradually and the distance between dendrites decr...
修正GTN模型及其在预测硅钢冷轧边裂中的应用
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...
获得抑制剂法生产低温高磁感取向硅钢的抑制剂控制研究进展
综述了国内外大钢铁企业与研究机构采用获得抑制剂法生产低温高磁感取向硅钢的开发及应用情况,分析了以该法生产高磁感取向硅钢过程中抑制剂的控制技术,包括固有抑制剂组成方案、气态渗氮方式与工艺及高温退火工艺的制定.研究表明,固有抑制剂组成方案的设计思路大体一致,化合物抑制剂以AlN为主、硫化物为辅,同时添加少量Sn,Sb等单元素抑制剂,但组成元素含量存在一定差别;在脱碳退火后用NH3进行非平衡渗氮处理已成为气态渗氮的主要方式,但最佳方式仍未明确,具体选择需依据实际生产条件,相应脱碳及渗氮工艺的控制条件差别较大;高温退火工艺中升温制度差别不大,升温阶段退火气氛中N2含量的选择存在差别.此外,分析了抑制剂控制技术目前存在的关键问题,并指出了进一步的研究方向. The current application and exploitation on production of low-temperature high magnetic induction grain-oriented silicon steel with acquired inhibitor method at both iron and steel enterprises and research institutions in the world are reviewed. The control techniques of inhibitors, which include the composition design for inherent inhibitors, nitriding method and process, and secondary recrystallization annealing, are thoroughly analyzed and proposed. It is indicated that the design ideas for i...
