温度对渗铝层生长动力学的影响和稀土的行为研究

Effect of Temperature on Growth Kinetics of Aluminizing Layer and Behavior of Rare Earths

分别研究了工业纯铁在710℃、740℃、770℃条件下热浸镀纯铝和稀土铝后合金层厚度随浸镀时间的变化,将其代入化学热处理的基本经验公式,经一元线性回归处理,证明了合金层生长动力学为抛物线型,并且稀土对动力学各阶段都有影响。在710℃和740℃时稀土作用明显,在770℃时作用较弱。试验结果表明,稀土渗入了合金层,并使渗层增加25%～30%;扩散激活能分别降低3155J/mol、3712J/mol和1339J/mol。讨论了稀土在热浸镀铝中的行为。

This paper has studied the effect of rare earths on the thickness of Fe-Al alloy layer of pure iron using hot dip aluminizing method at 710 ℃,740 ℃ and 770 ℃ in different periods. These thickness values and its corresponding time are substituted into the experience formula of chemical heat treatment, and processed by mono-linear regression, which leads to the result that the variations of the thickness of Fe-AI alloy layer with hot dip aluminizing time follows square parabola law, and the RE has influence on all hot dip aluminizing stages. The effects of RE are stronger at 710 ℃ and 740 ℃, but weaker at 770 ℃. The experimental results show that rare earths elements permeate alloy layer, and increase the thickness of Fe-Al alloy layer by about 25%--30% and the diffusion activation energy is decreased by 3155 J/mol, 3712 J/mol and 1339 J/mol respectively. The permeation and catalytic mechanism of rare earths are also discussed.