论文部分内容阅读
通过SEM,EDS和XRD研究了Ce对HP40Nb热浸镀铝层组织结构和高温抗氧化性能的影响。结果表明,热浸镀过程中添加质量分数1%Ce促进了镀层外层中Fe2Al5和Fe4Al3Ce相的生成,抑制了内层Fe2Al5相长大;在1 000℃/4 h扩散处理过程中,Ce促进了γ向α相的转变以及α相中Ni3Al相的析出,并在渗层内层中生成富Ce相;800℃/360 h氧化后,Ce促使渗层外层生成少量Fe2Al5和Cr3Si相,并使渗层外层组织均匀致密;1 000℃/360 h氧化后,Ce促使α相长大导致渗层中生成大量的σ相。800℃氧化实验发现1%Ce使渗层组织致密,提高了渗层高温抗氧化性;1 000℃氧化实验发现1%Ce促进了渗层中σ相的生成,阻碍了Al原子的内扩散,保证了氧化过程中渗层表面生成α-Al2O3所需铝含量。
The effects of Ce on microstructure and high temperature oxidation resistance of HP40Nb hot-dip aluminum coating were studied by SEM, EDS and XRD. The results show that the addition of 1% Ce during the hot-dip coating promotes the formation of Fe2Al5 and Fe4Al3Ce phases and inhibits the growth of the inner Fe2Al5 phase. During the diffusion treatment at 1 000 ℃ for 4 h, Ce promotes Γ transformation to α phase and precipitation of Ni3Al phase in α phase and the formation of Ce-rich phase in the inner layer of the layer. After oxidation at 800 ° C for 360 h, a small amount of Fe2Al5 and Cr3Si phases were formed on the outer layer of the layer by Ce So that the outer layer of the outer layer of uniform and compact; 1 000 ℃ / 360 h after oxidation, Ce to promote the α-phase growth led to the formation of a large number of o-phase phase. 800 ℃ oxidation experiment found that 1% Ce make the nitrided layer dense and improve the high temperature oxidation resistance; 1 000 ℃ oxidation experiment found that 1% Ce promoted the formation of sigma phase in the diffusion layer, hindered the diffusion of Al atoms, To ensure that the surface of the oxide layer formed α-Al2O3 aluminum content required.