纳米化表面360℃脉冲等离子体渗氮研究

Study of the Surface Nanocrystallization Pulse Plasma Nitriding at 360 ℃

本文主要研究了3J33马氏体时效钢表面纳米化后,在360℃下脉冲等离子体渗氮0.5～24h之不同时间下的渗氮行为。通过硬度法测量了渗层的厚度。结果发现,在360℃下即可实现快速渗氮。当渗氮时间达8h时,渗层可达50μm以上,硬度为800HV0.05左右;但8h后时间再延长渗层没有明显的增加。用X射线衍射法标定了渗氮层中相的成分。结果表明,渗层中并不含Fe4N或Fe3N,而是含氮量较低的低氮化物FeN0.0324。纳米压痕试验表明,渗氮后渗层硬度可达13GPa左右,比未渗氮试样硬度高3倍以上。

Plasma nitriding of surface nanocrystallized 3J33 maraging steel at 360 ℃ for different time was studied. Microhardness test shows that the thickness of nitriding layer is up to 50 μm when nitriding at 360 ℃ for 8 h and the surface hardness is about 800 HV0.05. But nitriding layer is not growing remarkably with prolonging nitriding time after 8 h; The XRD results indicate that the nitriding layer is not composed of Fe4N and Fe3 N, but low nitrogen nitride FEN0.0324 ;Nano-indentation test shows that the hardness of the nitrided layer isabout 13 GPa, which is about 3 times higher than that of the original one.