共查询到19条相似文献,搜索用时 187 毫秒
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轧制过程中铝箔如出现较大裂口,会使生产中频繁断带,也影响使用质量、裂口已成为铝箔的主要缺陷。分析了铝箔产生裂口的原因,提出了预防措施,从而使铝箔裂口废吕率明显下降。 相似文献
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白点是钢的内部缺陷,又叫发裂。是钢中氢含量偏高和内应力共同作用的结果。奥氏体、铁素体和莱氏体钢一般不形成白点,而马氏体、贝氏体和珠光体钢易形成白点。16MnR属于低碳钢,一般说来其氢致裂纹敏感性较低,不易产生白点,但83年我们在50mm厚16MnR钢板拉力试样上连续发现两炉钢产生白点缺陷。本文介绍16MnR钢白点宏观、微观形貌、白点形成原因,并对白点断口微观机制进行探讨。一、白点的宏观、微观形貌 1。酸浸低倍特征钢板纵向的中央区有断断续续的小裂口,并具有一定的深度。由于多道轧制的原因,这些小裂口几乎和轧向平行。用放大镜可观察到小裂口两端稍尖、略呈锯齿状。 2。宏观断口及拉力试样上的白点特征在横向φ20mm拉力试样表面有“人” 相似文献
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针对攀钢100m长60kg/m重轨上腹腔轧疤缺陷严重的问题,统计分析了轧疤缺陷的分布规律,得出原除鳞装置设计造成重轨上腹腔存在除鳞盲区和死角是其主要原因。为此,对除鳞装置进行了改进,完全消除了轧件上腹腔的除鳞盲区。改进后,钢轨上腹腔轧疤缺陷下降了52.19%,产品一次合格率提高了13%以上,班产也在原基础上提高了30%。& 相似文献
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DONG Renze China Academy of Railway Sciences Beijing China Associate Professor Dept.of Science Technology Development China Academy of Railway Sciences Beiiing China 《金属学报(英文版)》1990,3(4):287-292
The thermal cracking and wear mechanism of rail wheel tread have been studied.The resultsshowed that the thermal cracking of rail wheel tread is related to the chemical composition(mainly the carbon content)and the hardness of the wheels.When the composite brakingshoes are used,the rate of wear of the wheel tread is related to the fracture toughness of thenewly-formed“white layer”i.e.the martensite.The thermal cracking proof wheels(55SiMn)so far developed has achieved significant operating results in practical use. 相似文献
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C.J. Liu M.F. Jiang Y.S. Wang J.J. Chen C.L. Li 《金属学报(英文版)》2005,18(6):701-706
The mechanisms of La in heavy rail steel were studied by means of experimental measurements, microstructure observation and theoretical analysis in the present work. For heavy rail steel, the state and the content of La were measured, and the mechanisms and the effects of La on sulfide inclusions, microstracture and properties of steel were determined. Strip-like sulfides disappear in heavy rail steel with La/(O+S)〉3.50, which is shown that the metallurgical function of modifying sulfide inclusions has been achieved by La. La can fine the grain size of the austenite in heavy rail steel. Under the experimental condition, the plasticity and the impacting toughness of heavy rail steel with 0.005wt% La can evidently be improved. 相似文献
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测试了稀土重轨闪光电阻焊热影响区粗晶区和细晶区连续冷却转变曲线,研究了闪光电阻焊对稀土重轨组织的韧性的影响,结果表明,闪光焊后热影响区粗晶区韧性下降较多,细晶区韧性有较大提高。 相似文献
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为使高速及重载道岔AT钢尖轨跟端锻造热处理后组织与性能满足最新标准和线路使用要求,采用自主研发钢轨全断面感应加热+喷风冷却生产线,对高速及重载道岔60AT2-U71MnG及60AT1-U75V在线热处理钢轨压型跟端进行了热处理工艺试验,观察了硬化层的显微组织,检测了钢轨化学成分、硬化层深度、表面硬度、断面硬度、抗拉强度... 相似文献
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In the present study, heavy rail steel was prepared by the process of vacuum induction furnace smelting, forge work and rolling. Effects of Rare earths (RE) on microstructure and mechanical properties of heavy rail steel were systematically investigated by metallographic microscope, SEM, integrated mechanical testing machine, impact tester and so on. Metallographic analysis shows that, a few of RE can evidently delay the growth of austenite grain and fine pearlite. When the RE content is 0.016%, both anneal... 相似文献