【作者】 刘仙山；

【导师】 王从祥；

【作者基本信息】 武汉理工大学 ， 材料学， 2003， 硕士

【摘要】 用低合金奥贝球铁(ADI)生产装载机齿轮在奥贝球铁的应用中是一个全新的尝试，因为装载机齿轮减速比小、扭矩大，对材料的强度、韧性、耐磨性要求较高。迄今为止，用ADI材料制造装载机齿轮的文献报导还很鲜见。本文通过大量的试验，对其进行系统的研究，获得了适合生产装载机齿轮的奥贝球铁材料及工艺。 本文研究了多种孕育剂以不同的加入量对球铁铁水进行二次复合孕育处理，比较不同二次复合孕育处理工艺对球化效果、球铁组织和力学性能的影响。优选适宜的二次复合孕育处理工艺，使之降低了贵重合金加入量，放宽了对原材料的要求，在使用地方生铁的生产条件下，可获得性能优异、质量稳定可靠的奥贝球铁材料。 研究了热处理工艺对奥贝球铁组织和力学性能的影响。发现采用退火工艺，可较大幅度提高其综合力学性能；奥氏体化温度和时间影响等温转变产物中残余奥氏体的稳定性；等温转变温度和时间影响残余奥氏体含量及贝氏体转变程度；奥氏体化工艺及等温转变工艺是影响奥贝球铁综合力学性能的关键因素。在采用“退火(900℃～910℃×3h后炉冷至600℃空冷)+奥氏体化(900℃×120min)+等温转变(370℃×90min)”的热处理工艺可获得综合力学性能较好的奥贝球铁。 利用三体橡胶轮磨损试验机和销盘式磨损试验机对在不同等温温度转变获得不同组织的奥贝球铁与20CrMnTi钢分别进行在干摩擦条件下和在润滑条件下、在低载荷磨损条件下和在高载荷条件下的耐磨性对比试验。发现280℃等温转变处理的ADI材料在低应力服役条件下、370℃等温转变处理的ADI材料在高应力服役条件下具有很好的耐磨性。 通过奥贝球铁齿轮在装载机上的实际使用，证明奥贝球铁齿轮能够取代20CrMnTi钢齿轮，满足装载机齿轮的使用要求。更多还原

【Abstract】 It is a brand-new attempt that ADI with low-alloy is used the material of loading vehicle gears. The loading vehicle gears require excellent mechanical properties. So far it has been a few articles about these application. The craft of ADI is studied and selected through a great deal of experiments in this paper.First, the second compound-gestation craft and its influence on spheroid graphite, microstructure and mechanical properties are studied. The content of costly metal (Mo.Ni) can be decreased and the limit about raw material can be fallen if the valid craft is adopted.Second, the heat-treatment craft and its influence on microstructure and mechanical properties are studied. The integrated mechanical properties can be improved if anneal craft is adopted. The stability of retained-austenite is affected by austenize temperature and time. The content of retained-austenite and the extent of bainite change are affected by austempered temperature and time. The craft of austenize and austempered is the most important factor. It can acquire ADI material with better integrated mechanical properties when the crafts of heat-treatment is anneal(stove cooling to 6005L and natural air cooling after 900℃~910℃×3h), austenize (900℃ × 120min) and austempered (370℃x90min)n.Third, the wear-resistant of ADI in different austempered temperature is compared with 20CrMnTi steel through the three-system and the pin-on-disc type abrasion experiment in this paper. The results show that the wear-resistant of ADI (austempered in 280ftL) is good at low load and the wear-resistant of ADI (austempered in 370tT) is better than 20CrMnTi steel after certain time abrasion in high load.Finally, the gears of ADI are analyzed after they have been run for one year in load vehicle. The result shows that ADI gears can replace the 20CrMnTi steel’s gears.更多还原