Dynamic globularization prediction during cogging process of large size TC11 titanium alloy billet with lamellar structure

The flow behavior and dynamic globularization of TCll titanium alloy during subtransus deformation are investigated through hot compression tests. A constitutive model is established based on physical-based hardening model and phenomenological softening model. And based on the recrystallization mechanisms of globularization, the Avrami type kinetics model is established for prediction of globularization fraction and globularized grain size under large strain subtransus deformation of TC11 alloy. As the preliminary application of the previous results, the cogging process of large size TCI 1 alloy billet is simulated. Based on subroutine development of the DEFORM software, the coupled simulation of one fire cogging process is developed. It shows that the predicted results are in good agreement with the experimental results in forging load and microstructure characteristic, which validates the reliability of the developed FEM subroutine models.     

中冶赛迪自主开发的国内最大型号开坯轧机牌坊在邯钢成功竖立

2011年4月28日,由中冶赛迪工程技术股份有限公司自主开发、子公司赛迪重工制造的BDCD（Breakdown mill of CISDI）1350开坯轧机牌坊在邯钢大型线施工现场成功竖立,也标志邯钢老区钢轧系统改造大型型钢工程的设备安装工作正式拉开帷幕。     

耐候H型钢圆角翘皮缺陷的成因分析与改进措施

针对马鞍山钢铁股份有限公司大H型钢分厂生产的Q345NQR2耐候H型钢圆角翘皮缺陷问题,采用金相显微镜和扫描电镜分析的方法,分析了缺陷形成原因。结果表明,翘皮缺陷与基体存在明显分层,为热轧工序孔型不合理,万能轧制时轧辊圆角对轧件圆角切肉,轧制过程中把金属压入轧件所致。通过优化开坯机孔型、调整万能轧机水平度等措施,有效减少了此类翘皮缺陷的发生,显著提升了产品质量和经济效益。     

Study on cogging force of permanent magnet linear synchronous motor

Presented the methods to obtain the cogging force of permanent magnet linear synchronous motors(PMLSMs), analyzed the characteristics of the cogging force,and provided a basis for reducing the effect of the cogging force. 2-dimensional finite element method(2D FEM) was used to solve the whole motor when its mover was at different position, so that the relation was derived between the cogging force and the mover position. The analysis results show that the cogging force between the two ends of the primary iron-core and the secondary permanent magnets (PMs) is sinusoidal function of the mover position under certain conditions only. Two proposed methods,namely direct and indirect methods, are applied to calculate the cogging force between the primary iron-core teeth and the secondary PMs. The agreement of the two methods is validated.     

操作条件对开坯机联杆折断的影响

1.绪言爱知钢铁公司现有的开坯机,从安装使用到现在为止,已发生了几次联杆折断事故,普遍认为,其原因是钢锭大型化,以及为改善内部质量而采取的大压下操作规程所致。这种事故,除了明显的设计失误外,一般认为是操作时超过了轧机的设计强度,在超负荷的情况下发生的。从这个观点出发,笔者针对联杆的折断事故,实测了现有操作状况下的转矩,用模型将转矩与应力状态的关系明确化,并据此确立了预测联杆寿命(至折断为止)的方法,使预测联杆折断事故的技术水平得以提高。现将其结果介绍如下。 2.研究工作的开展方法根据操作条件与联杆模型试验,对目前使用过的三根联杆的寿命进行计算并进行比较研究,研究工作的开展方法示于表1。     

三辊开坯轧机大压下、大延伸工艺设计与实践

小型轧钢厂采取合理可靠的孔型系统，优化配辊，实现了大压下、大延伸轧制，提高了轧制节奏，取得了预期效果。     

27SiMn轧制表面裂纹缺陷原因分析

通过采用化学成分分析、光学显微镜、扫描电镜和能谱仪等分析手段对27SiMn轧制开坯表面出现的裂纹缺陷原因进行分析,结果表明;27SiMn轧制开坯表面出现大量的裂纹缺陷主要是由于钢锭表层夹杂物聚集形成夹杂物铁素体带状组织缺陷,轧制开坯产生表面裂纹。