【作者】 张金民；

【导师】 文九巴；

【作者基本信息】 河南科技大学 ， 材料物理与化学， 2006， 硕士

【摘要】 热浸渗铝是一项将钢铁的表面强化、表面防护和表面装饰结合在一起的工艺技术。钢铁渗铝后可以增强其耐腐蚀、耐热及抗高温氧化等诸多性能从而大大的减少钢铁因锈蚀和磨损等造成的经济损失,延长钢铁件的使用寿命,提高经济效益。本文对热浸渗铝钢微观组织进行了比较深入的研究,研究了La对热浸镀铝合金层生长动力学的影响,并对热浸渗铝钢表面性能进行了测试与分析。TEM观察分析表明,热浸渗铝（稀土铝）钢合金层从表面到内部组织分别为非晶、纳米晶、Fe₂Al₅相、FeAl₂相、FeAl相、Fe₃Al相、AlFe₃C_0.5相。非晶、纳米晶之间有调幅组织衬度条纹,Fe₂Al₅相、FeAl2相上存在调幅组织。利用点阵驻波理论分析了调幅分解初期波长,从表面向内部初期波长从0.63nm向10.6nm逐渐增大。FeAl相、Fe₃Al相、AlFe₃C_0.5相上未出现调幅分解现象。热浸渗铝钢中存在杆状和近似圆形状Al₄C₃相。首次发现Al₄C₃相以孪晶方式存在,并且发现六方晶系中存在以（003）为孪晶面,以[001]方向为旋转轴的180o二次旋转孪晶。Al₄C₃相的（003）面平行于杆的长轴方向,[001]方向垂直于杆的长轴方向,杆的长轴生长方向为[210]。FeAl相上有超点阵位错。Fe₃Al相上有反相畴。TEM观察在热浸渗La0.5%（wt%）的试样中找到了含La相。发现Fe3Al与AlFe₃C_0.5之间具有以下取向关系:利用工业纯铁分别进行热浸镀纯铝和热浸镀稀土铝,考察稀土（La）对热浸镀的影响,结果表明,稀土镧渗入了合金层,并对热浸更多还原

【Abstract】 Hot-dip aluminizing is a technology that integrates with strengthening, protection and decoration on the surface of iron and steel. It can intensify a lot of properties of iron and steel in corrosion resistance, resistance to heat and oxidation resistance at high temperature, decrease the economic loss by corrosion and abrasion, prolong the life of ferrous products greatly and bring good benefits. In this paper, effect of rare earth elements on kinetics of hot dip aluminizing was studied, the microstructure of hot dip aluminizing was studied by TEM. Some performance of hot dip aluminizing was explained through the microstructure.The cross section microstructure and composition of coating hot-dipped with Aluminum were analyzed by TEM . The results show that the microstructure of coating are respectively amorphous, nano-crystalline,Fe-2Al₅,FeAl₂,FeAl,Fe3Al,AlFe3C0.5 from surface to inner coating. There are spinodal decomposition structures in amorphous, nano-crystalline , Fe-2Al₅ and FeAl₂ . The wavelengths of spinodal decomposition at initial stages were analysed by the theory of static lattice waves. There wavelengths were gradually augment from 0.63nm to 10.6nm from surface to inner coating. there are not spinodal decomposition structures in FeAl,Fe3Al,AlFe3C0.5. The Al₄C₃ phases in hot-dipped aluminum steel were club-shaped and approximately rounded. The Al₄C₃ phases existed in hot-dipped aluminum steel as twins. And the 180o secondary rotary twins with （003）as twin surface ,更多还原