Alloy optimisation of bainitic steel for large plastic mould

Based on the phase transformation theories, especially the T₀ concept of bainite transformation, alloy optimisation of bainitic steel with carbides has been carried out aiming at the produce of plastic mould with large cross-section. The effect of manganese and silicon on proeutectoid ferrite and bainite transformation is explored by dilatometric analysis, XRD and different microscopy techniques. The results show that after the alloy optimisation, the transformation of proeutectoid ferrite is suppressed and when the cooling rate is lower than 0·1°C?s^??1, the new lower bainite transformation appears by decreasing carbon capacity of austenite and promoting carbide precipitation. Industrial production proves that the optimised alloy SDP1 can meet the demand for the plastic mould with the thickness of 1050?mm.     

Liquid steel flow in continuous casting machine: modelling and measurement

Abstract

Single phase (liquid steel) and two-phase (liquid steel and argon bubbles) three-dimensional computational fluid dynamic and heat transfer models were developed for the continuous casting machines of ArcelorMittal. The computational domains include tundishes, slide gates, submerged entry nozzles and moulds. The effects of buoyancy, tundish design, tundish practices, nozzle design and caster practices on flow structure were investigated. Mathematical modelling is discussed in detail. In addition, submeniscus velocity measurements in the slab caster mould are performed with the method of torque measurement. A consumable probe is inserted into the liquid steel meniscus from the top of the mould through mould powder and slag layer. The liquid steel flow applies a drag force to the probe, which then generates a torque. This torque value is measured and then converted back to velocity. The concept and challenges of the technique are discussed, and the effects of casting parameters on mould flow structure are investigated. Product quality in relation to real time meniscus velocity measurements is also discussed.     

Controlling delivery and energy performance of parallel batch processors in dynamic mould manufacturing

Given the mounting concern about service levels and environmental sustainability, mould industry is facing growing pressure to improve delivery reliability and energy efficiency. While heat-treatment operation is a bottleneck that affects related performances in mould manufacturing. Effective production control of this operation is essential to improve the on-time delivery and reduce the energy consumption of the mould. The operation often involves parallel batch processors and incompatible jobs, which allows for simultaneous processing yet with same job family and different weights and due dates. This paper considers the batch process control of parallel processors for dealing with such non-identical jobs in dynamic environments. An event-driven look-ahead batching strategy called MLAB-DE has been proposed. In MLAB-DE, the individual decisions for each family excluding the effects of these decisions on other families are suggested firstly. Then each alternative decision by including its effects on all families is evaluated. MLAB-DE is used to control two kinds of conflicting objectives related to the delivery and energy performances and finally achieve trade-off based on two-level compromise programming model. Simulation study is conducted to verify the effectiveness of the MLAB-DE strategy and show that the results are promising as compared to benchmark rules.     

自动化立体仓库系统在飞机钣金模具管理中的应用

通过设计与规划自动化立体仓库管理系统,提出了以满足工段生产需求为目标的物流配送思想,以此思想为导向,优化模具管理流程,理顺内部客户关系,实现了飞机钣金零件模具的高效、准时配送。在飞机钣金模具管理中,与传统的模具仓库管理模式相比,自动化立体仓库系统节省了场地面积,降低了人工成本,提高了零件生产效率。     

水泥电杆模具翘尾问题研究

水泥电杆在离心成型过程中,常遇到模具震动的现象。本文讨论了模具近梢端部分翘起引起模具震动的情况。提出了以限制翘起度来防止模具震动。     

铸型材料和铸板厚度对Ti-6Al-4V钛合金微观组织的影响

基于组织定量分析技术,研究了铸型材料和铸板厚度对Ti-6Al-4V钛合金成形性能及成形后铸板的微观组织中原始β晶粒尺寸和α片层间距的影响.结果表明,铸型材料和铸板厚度对Ti-6Al-4V钛合金的成形和成形后的微观组织具有重要影响.石墨铸型相比陶瓷铸型具有较差的成形能力,铸件的微观组织也明显细化.随着铸板厚度的增加,原始β晶粒尺寸、α片层间距呈近线性上升的趋势.     

注塑模具流道数控铣削加工编程方法研究

通过在对注塑模具流道数控铣削加工与NX编程软件研究的基础上,总结出了注塑模具流道数控铣削加工编程方法,并讨论了其实际应用的优缺点,对于模具生产加工具有实用价值。     

塑料模具激光蚀纹机的关键技术研究

在塑料模具蚀纹加工中,传统的化学蚀刻方法存在污染大、加工周期长的缺点.基于最新的3D动态振镜扫描技术,对模具激光蚀刻原理进行了分析和探讨;对模具激光蚀刻工艺参数进行了优化;并设计了塑料产品常见的蚀纹图案.经过对模具激光蚀纹机的光学系统、机械系统、电气系统及软件系统等整体方案的设计及丁艺实验,证明模具激光蚀刻技术能满足了塑料模具加工企业的蚀纹和环保节能需求,同时为激光加工技术在塑料模具行业的广泛应用奠定基础.     

浇铸主要工艺参数及保护渣性能对模铸钢锭实物质量的影响

对贵钢一炼钢厂2010年1～6月份模铸钢锭裂纹缺陷及冒口部位收缩突出,严重影响钢锭质量的问题,利用钢液结晶凝固的普遍原理优化模铸生产工艺参数,并在改进固体保护渣成分、性能的基础上得以完全解决。