球墨铸铁表面激光重熔工艺资料.doc

目 录 摘 要 1 ABSTRACT 2 1 绪论 1 1.1 球墨铸铁 1 1.1.1 球墨铸铁的发展 2 1.1.2 球墨铸铁的分类 4 1.1.3 球墨铸铁的基体组织 6 1.1.4 球墨铸铁的机械性能 8 1.1.5 球墨铸铁表面改性 10 1.2 激光重熔技术 11 1.2.1 激光重熔的特点 12 1.2.2 激光重熔工艺参数的选择 14 1.2.4 激光重熔技术工业应用实例 15 1.3 实验的目的和意义 15 2 实验材料及方法 16 2.1 实验材料 16 2.2 实验仪器 17 2.3 实验过程 17 2.3.1 线切割 17 2.3.2 激光重熔 17 2.3.3 镶嵌 19 2.3.4 预磨与抛光 19 2.3.5 腐蚀 20 2.4 宏观形貌与显微组织分析 20 2.5 显微硬度测试 20 3 结果与分析 21 3.1 激光重熔显微组织金相分析 21 3.2硬度分析 28 参考文献 32 致 谢 35  摘 要 球墨铸铁是一种高强度的铸铁材料，由于其应用广泛的机械性能、成本低廉、工艺简单等优点，球墨铸铁已迅速发展为产量仅次于灰铸铁的铸铁材料。虽然球墨铸铁铸件已经在所有主要的工业领域中得到广泛的应用，但是由于球墨铸铁的硬度较低，耐腐蚀性能亦较差等缺点，在很大程度上都限制了球墨铸铁的应用，而对球墨铸铁表面进行激光重熔工艺处理，可以有效提高球墨铸铁表面的硬度、耐腐蚀性和耐高温性等，将大大扩展球墨铸铁铸件的应用范围，是一种有着广大前景的工艺。 本文用功率为1500 W、2000 W和2500 W的光纤激光束（光斑直径为5 mm×5 mm），以6 mm/s的扫描速度辐照珠光体球墨铸铁表面，然后用VHX-600K型超景深三维数码显微分析仪观察了激光辐照后珠光体球墨铸铁表面重熔层及热影响区的微观组织，用HXD-1000TM/LCD自动转塔数显显微硬度计Processing experiment of laser remelting on Ductile cast iron ABSTRACT Ductile cast iron is a kind of cast iron material with high strength, its application in a wide range supported by its mechanical properties, low cost, simple process, these merits prompted it outnumbered other cast iron materials expected the gray cast iron. Although ductile iron castings have been applied widely in all the major industrial areas , due to the bad performance of corrosion resistance and low hardness of nodular cast iron , it is confining its use in many areas.Processing of laser remelting on nodular cast iron can improve its surface hardness and corrosion resistance and enduring high temperature and consequently widen the range of application. The procession is promising. The powers of the laser beam used in this paper are 1500、2000 and 3000wat, with the scanning speed 6mm/s casted on the pearl uctile cast iron. Then using the VHX-600K with supper depth of focus three-dimensionally investigated the processed materials remelting layer and the heat affected zone. And HXD-1000TM/LCD to measured the hardness of remelting layer’s section of pearl nodular cast iron. After disc