【作者】 张丽辉；

【导师】 王强；

【作者基本信息】 吉林大学 ， 材料加工工程， 2006， 硕士

【摘要】 本文着重研究了铁素体球墨铸铁冲击韧性的改善途径,尤其是低温冲击韧性的改善。通过试验制定了合理的球化与孕育工艺,并分析了热处理方法、化学成分以及冷却速度对球墨铸铁的组织和冲击韧性的影响。结果表明:采用稀土镁球化剂球化处理,加入量为1%,孕育处理为0.6%硅铁75浇包孕育,并且采用快速冷却的方法能够保证得到良好的球化和孕育效果,石墨球圆整细小,数量较多。采用两阶段退火可以保证得到100%的铁素体基体组织。同时将化学成分控制为3.3～3.7%C,1.5～2.0%Si,Mn≤0.2%,S≤0.03%,P≤0.07%,铁素体球墨铸铁的冲击韧性尤其是低温冲击韧性较高。本文还对高韧性铁素体球墨铸铁与低碳钢的摩擦焊做了初步探索。研究了摩擦焊接头的组织性能,探讨了其摩擦焊接性。结果表明:在合适的焊接工艺参数下,球墨铸铁与低碳钢的焊接接头具有一定的强度,采用摩擦焊的方法焊接球墨铸铁与低碳钢是可行的。更多还原

【Abstract】 The way of improving room-temperature and low-temperature impacttoughness of ductile cast iron has been studied in this article. Reasonablenodularization and inoculation technology were established through someexperiments. The effects of heat treatment, chemical composition and coolingspeed on structure and impact toughness of ductile cast iron have been analyzed.The results achieved are: Nodularization treatment used RE-Mg nodularizer,the amount of which was 1%. Inoculation treatment used 0.6%75SiFe in ladleinoculation. The way of fast cooling was adopted. The technique ensured theeffects of nodularization and inoculation. Spherical graphite gained was small andthe number of spherical graphite was more. Ductile cast iron gained ferrite baseby two-stage annealing. At the same time, room-temperature and low-temperatureimpact toughness of ductile cast iron were excellent when chemical compositionwas 3.3～3.7%C,1.5～2.0%Si,Mn≤0.2%,S≤0.03%,P≤0.07%.The friction welding of ductile cast iron and low carbon steel has been stillexplored in this article. The weldability and mechanical property of the weldingjoints have been studied. The results show that under certain welding parameter,the joints of ductile cast iron and low carbon steel were sound, and the joints hadadequate strength. So the friction welding was fit for ductile cast iron and lowcarbon steel.更多还原