合金钢脆性网络的加工和破碎实验研究

发布时间：2018-01-31 09:51

本文关键词： 弹壳材料等离子表面淬火激光表面淬火冲击性能脆性组织　出处：《沈阳工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来，许多国家为了提高炮弹的破片率而提出改变弹体材料性能的方案，其中预置破片和机械刻槽这两种方法是比较常用的，但这两种方法的成本比较高且预制破片极大消耗各国的战略储备，所以必须要改进现有的弹壳加工工艺。本课题提出利用激光淬火、等离子淬火、钨极氩弧淬火等加工方法，在弹壳表面加工出不同密度的脆性带网络，在爆炸时会在加工处优先断裂，形成质量均匀、形状规则的可控破片，代替原有的加工方法，并将试件做整体淬火作为对比。在实验中，将40Cr、50SiMnVB、58SiMn三种材料加工成片状试件，分别用上述方法加工出不同密度的脆性带网络，对其进行冲击破碎实验，结果表明：脆性带的密度对试件断裂影响不大，但是否加工脆性带对冲击结果影响显著。综合来看，，三横三纵型脆性带由于破片率较高且需要破碎的能量较小，所以破碎效果最好；材料因素对试件的断裂有一定影响，但仍不如是否加工了脆性带的影响显著。用ANSYS有限元分析软件得出的结论为：脆性带的偏移量和密度对弹壳破碎难易程度影响很小，与实验结果基本相符。通过扫描电镜和能谱仪对脆性带的脆化机理进行分析，结果表明：用3种加工方法加工出的脆性带在材料表层一定深度范围内生成了脆化组织，且没有成分流失和聚集，还伴随有少量微裂纹产生。同时还用显微硬度计对脆性带的硬度进行测量，结果表明：脆性带的硬度与基体相比得到明显提高。综合以上分析方法和实验结果得出最优的加工方案：采用激光方法加工脆性带，加工速度20mm/s，功率500W，脆性带类型为三横三纵型。
[Abstract]:In recent years, in order to improve the fragmentation rate of projectile, many countries have put forward the plan of changing the material performance of projectile, among which the two methods of preset fragment and mechanical groove are commonly used. However, the cost of the two methods is high and the prefabricated fragments consume the strategic reserves of each country greatly. Therefore, the existing process of shell case processing must be improved. In this paper, by using laser quenching, plasma quenching, tungsten argon arc quenching and other processing methods, the brittle band network with different densities is machined on the surface of the shell case, which will break preferentially in the process of explosion. The controlled fragment with uniform quality and regular shape was formed instead of the original processing method and the sample was quenched as a contrast. In the experiment, three kinds of materials 40Cr50SiMnVBN58SiMn were processed into flake specimens, and the brittle band networks with different densities were fabricated by the method mentioned above. The results show that the density of brittle zone has little effect on the fracture of the specimen, but whether the brittle zone is processed has a significant effect on the impact results. Because the fragment rate is high and the energy needed to be broken is small, the breakage effect is the best in three transverse and three longitudinal brittle zones. The material factor has certain influence on the fracture of the specimen. But it is not as good as whether the brittle zone is machined or not. The conclusion obtained by the ANSYS finite element analysis software is that the migration and density of the brittle band have little influence on the easy degree of fragmentation of the shell case. The results are in good agreement with the experimental results. The embrittlement mechanism of brittleness band was analyzed by SEM and EDS. The results showed that embrittlement structure was formed in a certain depth of the surface layer of the brittleness zone processed by three kinds of processing methods. There is no loss and accumulation of composition, and a small amount of microcracks are produced. The hardness of brittle band is also measured by microhardness meter. The results show that the hardness of the brittle band is obviously higher than that of the matrix, and the optimum processing scheme is obtained by synthesizing the above analysis methods and experimental results: the processing speed of the brittle band is 20mm / s by laser processing. Power 500 W, brittleness band type is three horizontal and three vertical.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG156.3;TJ410.5

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