消失模铸造钢爪工艺的改进

通过对消失模铸造钢爪生产工艺的改进,采用顶注式,配以在钢爪两臂与爪交界处设置暗冒口的工艺,不仅简化了铣工序的复杂性,提高了生产效率,而且还降低了生产成本,提高了企业的经济效益和市场竞争力。     

负压气流消失模铸造工艺对铸钢件组织和性能的影响

介绍了一种运用负压气流的消失模铸造工艺。测试了分别由负压气流消失模铸造工艺和水玻璃砂型铸造工艺生产的ZG35钢和ZGMnl3钢的碳含量、金相组织及力学性能。结果显示，负压气流消失模铸造工艺可以有效地避免铸钢件的表面增碳和体积增碳，同时加速金属液的凝固，细化铸件晶粒。用其生产的铸钢件在力学性能方面与水玻璃砂型生产的相差很小。     

消失模工艺在艺术品铸造中的应用

阐述了消失模铸造艺术品工艺特点，并详细描述消失模铸造工艺品实例——铜钟整个消失模铸造工艺过程。展示了中大型工艺品采用消失模铸造的优越性。     

消失模铸造和V-法铸造

1 消失模铸造和V-法铸造比较 采用消失模铸造的厂家或车间,在铸件的生产过程中,有些铸件改用V-法铸造更加合理,投入少,产出多,因为V-法铸造与消失模造有着共同的主要设备和工艺。消失模铸造工艺流程如图1,V-法铸造工艺原理及流程如图2。     

消失模铸造法

消失模铸造法机械部济南铸锻机械研究所金宏骥１国内外概况消失模铸造法（ＥＰＣ），也称实型铸造、气化模铸造等等。各国名称叫法不统一，为方便起见，以美国铸造学会消失模铸造委员会，１９９０年夏天正式采用的消失模铸造法（ＥＰＣ）为这一工艺的通用标准名，我们以下...     

灰铁气缸盖消失模铸造工艺调试

介绍了灰铁气缸盖消失模铸造工艺在中小企业实践的一些体会。气缸盖是结构复杂铸件，对消失模铸造材料及其工艺要求都比较严格，国外及国内部分铸造企业已经用于生产。但是在条件较差的我国中小铸造企业如何创造条件，在现有的条件下将其铸造成功，是广大中小铸造企业非常关心的问题。通过工艺试验和批量试生产，对气缸盖消失模铸造工艺进行了有益的探索。     

圆柱面桥梁支座燃烧除碳法消失模铸造

YZM系列圆柱面支座是一种新型铁路桥梁钢支座,采用消失模铸造工艺生产铁路桥梁钢支座有许多优点。介绍了模样燃烧消失空型壳消失模铸造的工艺过程,研究了燃烧除碳法的模样材料性质、涂料、真空负压等主要因素的影响。实践证明这种工艺方法可有效地解决铸钢件的增碳缺陷问题。     

V法铸造与消失模铸造的比较及复合铸造实践

对V法铸造与消失模铸造进行了比较。列举两个实例说明V法与消失模复合铸造工艺,介绍了V法铸造中使用消失模泡沫模块工艺,提高了造型效率,保证了铸件质量。     

铸钢爪的消失模铸造浇冒口合一工艺

针对铝电解用阳极爪架的结构特点,从模型制备、涂料、干砂振动紧实、浇注等方面分析了铸件的消失模铸造工艺。经实际生产验证,采用消失模浇冒合一的工艺可提高生产效率,降低生产成本,并减少对环境的污染。     

铝电解用阳极爪架的消失模铸造工艺

针对铝电解用阳极爪架的结构特点,从模型制备、涂料、干砂振动紧实、熔炼及浇注等方面分析了铸件的消失模铸造工艺。经实际生产验证,采用消失模工艺可提高生产效率,降低生产成本,并减少对环境的污染。     

压铸模具钢的选用浅析

为了获得更好的压铸模具寿命,有必要研究模具损坏的主要原因。模具失效主要是由于裂纹和冲蚀,保证工具钢的耐热性使其具有良好的高温强度,高温韧性和热传导性是关键。对热作模具钢进行了热疲劳性,热导率、横向冲击韧性及组织热疲劳裂纹的数据比较,选择正确的热作工具钢能大幅度提高模具寿命。结果表明,正确选择压铸模用钢,能提高模具的产品质量和延长使用寿命,且生产效率高、经济效益好。     

薄板坯连铸低碳冷轧用钢保护渣的研究与开发

介绍了唐钢薄板坯连铸低碳冷轧用钢保护渣的研究开发过程.通过漏斗形结晶器与保护渣性能匹配的关系研究、保护渣组成和物性研究、多次生产试验和性能优化,最终开发出满足工艺要求的国产低碳钢保护渣,保证了低碳冷轧用钢的稳定生产.     

Prediction of burn-on and mould penetration in steel casting using simulation

Abstract

Burn-on and penetration defects in steel casting are principally caused by localised overheating of the sand mould or cores. Such overheating can cause liquid metal to compromise the mould surface and entrain onto the surface of the mould. A method has been developed to predict likely burn-on and penetration defect locations as part of a standard casting simulation. The method relies on determining, from simulation results, the locations where the mould is above a certain critical temperature. The critical temperature is generally above the temperature at which the steel is fully solidified. By measuring the time periods during which these locations in the mould are above the critical temperature, burn-on and penetration defects can be predicted. The method is validated through comparison with previous experimental data. Several parametric studies are conducted to investigate the sensitivity of the predictions to the choice of the critical temperature, the interfacial heat transfer coefficient between the steel and the mould, the pouring temperature, and the mould material. The results of one case study are presented where burn-on or penetration defects observed on a production steel casting are successfully predicted.     

Solidification microstructure of M2 high speed steel by different casting technologies

The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies,namely iron mould casting and continuous casting.The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks,which were greatly refined in the ingot made by continuous casting process,compared with that by the iron mould casting process.M2C eutectic carbides presented variation in their morphologies and growth characteristics in the ingots by both casting methods.In the ingot by iron mould casting,they have a plate-like morphology and grow anisotropically.However,in the ingot made by continuous casting,the carbides evolved into the fiber-like shape that exhibited little characteristics of anisotropic growth.It was noticed that the fiber-like M2C was much easier to decompose and spheroidize after heated,as a result,the carbides refined remarkably,compared with the case of plate-like carbides in the iron mould casting ingot.     

Prediction of distortions and pattern allowances during sand casting of a steel bracket

Mechanical interactions between the casting and mould generate unwanted distortions and lead to dimensional inaccuracies. In this study, the effects of mould expansion and mould restraint are investigated through sand casting experiments involving a U-shaped steel bracket. Distortions are quantified by in situ measurements of the evolution of the gap opening between the bracket legs. Mould expansion is observed immediately after filling. Outer mould restraint prevents distortions in the bracket legs until the time of mould fracture, after which the legs are pushed outward. The experiments are simulated using a sequential thermo-mechanical coupling. The steel and bonded sand are modelled using previously calibrated elasto-visco-plastic and Drucker–Prager Cap constitutive laws, respectively. Excellent agreement between measured and predicted pattern allowances (PA) is obtained. Distortions are greatly under-predicted unless mould fracture is considered. Variations in the packing density of the moulds are also shown to have an impact on PA.     

微合金化钢连铸坯边角部无缺陷生产技术开发

以邯宝炼钢厂板坯连铸机为依托,以实际生产的典型铌、钒、钛微合金化钢为研究对象,系统研究了板坯表面裂纹缺陷形成机理,确定了倒角结晶器窄边铜板的最佳角度和最佳倒角长度;设计并开发了具有组合式冷却水道的倒角结晶器窄面铜板,适用于带倒角连铸坯的新型支撑足辊系统;结晶器窄侧锥度的设计及应用管理,有效支撑了带倒角连铸坯的窄边,解决了角纵裂及角纵裂漏钢的难题,提高了结晶器窄边铜板的使用寿命,同时为连铸的高拉速提供了保证。项目突破了倒角结晶器技术工业化应用的技术瓶颈,从根本上解决了微合金化钢连铸板坯角部横裂纹问题,成功实现了大规模工业化稳定生产。     

高拉速薄板坯连铸结晶器钢渣界面波动分析

为应对提高拉速薄板坯结晶器内钢液不稳定行为,以1 520 mm×90 mm薄板坯结晶器为研究对象,利用液面追踪技术VOF方法建模计算,对薄板坯钢渣界面进行了深入研究,实现了对薄板坯连铸结晶器内流体流动及钢/渣界面行为的模拟计算。并结合实际生产工艺,采用1∶1物理模型和数值模拟相互验证,分析了拉坯速度、浸入深度和保护渣黏度种类对结晶器流场及钢渣界面的影响。结果表明,当结晶器钢液面流速为0.20~0.25 m/s,且界面较平稳时,保护渣黏度高于0.237 Pa·s可以适用;当钢液流速为0.25~0.30 m/s,保护渣黏度为0.382 Pa·s时,现场低碳钢卷渣率小于0.5%,表现出良好的抗卷渣能力。     

Effect of mould material on aluminum alloy ingot quality under low frequency electromagnetic casting

F or a semi-continuous aluminum casting process, it is essential to supply high quality aluminum alloy ingot without internal and outside defects. The use of electromagnetic fields to control the size and shape of grains has become one of the most promising methods [1-5] in many engineering applications and tends to be widespread in industries. The application of electromagnetic casting (EMC) technique for improving products quality has attracted a great deal of attention in recent years, and…     

越南某钢厂小方坯连铸试生产失稳性诊断分析

越南某钢厂六流方坯连铸机在投产后的试生产过程中,生产很不稳定,事故停机频发,拉坯速度不超过2.5 m/min,试生产前期主要是漏钢停浇,后期主要是中间包快换水口盲板自动关闭停浇。通过对生产现场的工艺条件、操作流程、设备配置与工作状态等各方面的观察和排查,结合连铸漏钢机制、自动停浇诱因对事故进行了分析,提出从浇注操作的规范与熟练、结晶器振动的可靠性、水口质量、结晶器卷渣、切后铸坯拥堵的人工干预等方面进行改进的措施。逐步落实各项改进措施后,目前该厂生产平稳,拉速达到了3.25 m/min,漏钢及水口盲板自动关闭停浇等生产事故得到了显著改善。     

微电机转子压铸模设计

给出了微电机转子实用的模具结构和压铸工艺,论述了模具的设计要点.采用镶块、镶套结构,不仅节省模具钢,而且改善了模具的排气性,提高了产品的质量.