Development of ultra light magnesium-lithium alloys

Magnesium-lithium alloys are among the lowest density metallic materials. Addition of lithium, with a relative density of 0·53, in magnesium reduces the density of the alloy significantly. Furthermore, addition of nearly 11 wt.% lithium converts hexagonal close packed structure of pure magnesium to a body centered cubic lattice, markedly improving formability of the alloy. The development of these alloys, however, had been hampered due to the high reactivity of lithium and magnesium in the molten state and also, due to poor creep resistance and instability of mechanical properties at room temperature. In an attempt to indigenize these ultra light alloys for possible applications in Indian satellite programme, detailed research work was initiated in DMRL. The difficulties associated with producing sound cast ingots have been overcome by controlling melting and casting parameters of these alloys. Extensive work has been done on structure-property correlation of alloys with varying lithium content and minor alloying additions. Based on these work, advanced magnesium-lithium alloys have been developed with improved tensile properties, room temperature stability and creep resistance. Wrought products (plates/sheets) of magnesium-lithium alloy have been supplied to ISAC, Bangalore and are being used in their INSAT-2 programme. This paper describes the systematic studies carried out in the laboratory to indigenize these ultra light alloys.     

攀钢转炉炼钢用碳化硅提温的试验研究

低品位碳化硅是转炉炼钢的有效提高温剂。工业性试验结果表明，碳化硅加入８．０ｋｇ／ｔ钢水提温４０．３－７０．３℃（平均４８．４℃）；渣中ＴＦｅ降低１．３％；加提温剂有利于转炉内造渣脱硫和碱少炉渣对耐火砖的侵蚀。文中还给出了攀钢转炉半钢冶炼铸用钢不水时加与不加碳化硅的ｔλ，［Ｃ］λ区域。     

1100℃以上高温连铸板坯表面缺陷的模拟在线无损检测

高温状态下连铸板坯表面缺陷的在线无损检测在现代化的连铸坯热送－直轧工艺中对于保证铸坯的质量有着极其重要的意义。本文介绍了连铸坯高温探伤技术和相应的试验装置。采用涡流方法成功地模拟了１１００℃以上铸坯表面缺陷的动态检测，所用探头及检测设备均可在高温状态下长时间连续工作，能检测出深度为１．５ｍｍ，宽度为０．３ｍｍ，长为１０ｍｍ的表面缺陷，并能有效地抑制铸坯表面振动斑痕所产生的噪声影响。借助于计算机信号     

水冷热模法离心铸造大口径球铁管用管模涂料

阐述水冷热模法管模涂料的组成。说明了耐火基料，悬浮剂、粘结剂，减水剂的各自作用机理，提出了合理的涂料配方、合适的喷涂方式。     

连铸坯红送热装应用效果分析

对加热炉用连铸坯红送热装效果的分析结果表明，该技术的应用可节能降耗，提高产量和加热质量。     

消失模铸造模成型机的特点及应用

介绍了消失模铸造工艺对成型机的特殊要求,高性能成型机在大规模工业化消失模生产中的重要性,重点阐述了德国Teubert公司TVY130/90消失模成型机的特点及应用,并对成型机的国产化研究与开发提出了建议。     

提高连铸浊环水水质浅析

介绍了太钢板坯连铸水处理系统的工艺流程，分析了连铸浊环水水质存在的问题。通过对冷却塔部分、铁皮坑、水泵调速等改造，以及选用新的水质稳定剂，使水质明显好转。     

消失模生产中应用表面光泽涂料防止球铁件产生夹渣缺陷

以汽车弹簧托架为实例，分析用EPC法生产球铁件时产生夹渣缺陷的原因，提出采用表面光泽涂料可有效防止夹渣缺陷的产生，同时亦可改善铸件表面粗糙度。