控制W9Cr3Mo4V低倍碳化物剥落的工艺改进

针对W9Cr3M04V轧制成品材低倍碳化物剥落的形成原因分析，得出一次碳化物颗粒粗大、在1／4D至中心区域聚集是导致低倍热酸浸试验碳化物剥落的主因；由此进行冶炼过程中注速（锭形）、浇注温度选择对比工艺试验，得出在原有冶炼＋轧制的工艺基础上选用2．2t锭、降低浇注温度（1489℃）能有效改善一次碳化物颗粒大小和聚集程度，进而有效降低低倍碳化物剥落倾向。     

空心钢锭锻造工艺的研究

介绍了30t空心钢锭锻造试验过程及所制产品的质量情况,以及用65t空心钢锭生产电站环形锻件情况,为用大型空心钢锭生产锻件的进一步研究提供了依据。     

模铸中碳钢偏析的改善

简要介绍和分析了宝钢集团五钢公司改善模铸中碳钢头部碳偏析程度的技术措施。     

定向凝固锭技术文献综述

本文在查阅专利文献和其它相关文献的基础上对定向凝固锭技术作了回顾和总结 ,供有关人员参考。     

铝铸锭线上扒渣机的改进

介绍了扒渣机的基本原理，运用气动系统动力学的相关理论分析了它的动态特性，阐述了扒渣机产生振动冲击的主要原因和消除这些振动冲击的方法，对国产铝连续铸锭线的扒渣机具有重要价值。     

Process adjustment with an asymmetric quality loss function

Controlling an engineering process usually focuses on maintaining the process output on-target with minimum variation. Conventionally, the quality loss incurred by the deviation from the nominal values is assumed symmetric. However, in some engineering processes, the penalties incurred by positive and negative deviations of the quality variables are different. In such cases, we need to redesign the controller so that the overall quality loss is minimized. In this work, motivated by a real ingot growing process, a new controller is proposed for an asymmetric quality loss function. Its performance and stability are studied via numerical simulation. The effectiveness of the method is also demonstrated in the real engineering process.     

半连续铸造铝合金表面缺陷的形成机理及影响因素

介绍了半连续铸造铝合金锭坯冷隔、皮下偏析层、表面偏析瘤、拉痕等表面缺陷的特点和形成机制。分析了在半连续铸造铝合金锭坯过程中结晶器结构、铸造工艺参数对这些表面缺陷的影响及作用机理。在此基础上总结了提高铸锭表面品质的技术发展和工艺优化方向。     

铸铁钢锭模铸态残留应力初探

通过对合格的铸铁钢锭模的铸态残留应力的实际检测,发现当钢锭模内表层有“额外”石墨化时残留铸造应力呈不利状态;而无额外石墨化时残留铸造应力呈“拉内压外”的有利状态、无需时效热处理,并从而推荐了合理化学成分。通过实际检测还发现,沿用工艺铸得的锭模的弹性模数及泊松比值较低,且具有软的力学特性。     

7A52合金铸锭漏斗底结物形成原因

7A52合金铸锭时,分液漏斗底部常产生底结物。通过化学及SEM-EDS分析,发现底结物中Mn、Cr、Ti元素浓度分别超正常值约5倍、10倍、15倍。XRD分析表明其主要化合物相组成为Al7Cr、MnAl6、TiAl3。结果表明,底结物产生和形成原因主要与分配漏斗与液穴底的间距、分配漏斗的材质、铝熔体中的杂质等因素有关,同时也与铸造温度、分配漏斗预热等工艺条件有关。根据分析结果,提出了提高铸造速度、改变分配漏斗尺寸、对分配漏斗进行喷涂和预热等消除底结物的具体措施,并成功应用于生产实践。     

An Experimental Investigation on the Fabrication and Testing of Mechanical Properties of Aluminum-Silica Gel Metal Matrix Composite

A metal matrix composite (MMC) was fabricated using Al as the base metal which was reinforced by a ceramic material silica gel. This article shows detail fabrication stages in the production of MMC. The properties were considered with regard to the saturation point of the reinforcement of silica gel into the metal matrix of Al-Si alloy which was found out experimentally. Here the improvement of the mechanical properties of Al-silica gel MMC composite were studied with respect to that of pure Al-Si alloy. Different tests were conducted to show the results. Conventional ingot metallurgy with infiltration technique using vortex method had been employed in the fabrication process. The test results show that there are improvements by 17.14%, 13.46%, 11.48%, and 18.18% on compressive strength, impact strength, Brinell hardness value, and Rockwell hardness no respectively of Al-silica gel MMC over the pure Al-Si alloy.