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Question on plasma nitriding of steel

2004

Dear sir,

In my researches in plasma nitriding of 304 Austenitic stainless steel. And by using an optical microscope to obtain the lateral view of the nitrided sample . But the distinction between the compound zone and the diffusion zone couldn't be made. Why? and how can I recognize them? Also the thickness of the observed layer was=85 microns. Is this layer is the compound only or the summation of the two zone(case depth)? please help me .

Thanks,

Doaa Ibraheem
researcher - Cairo City, Nasser City, Egypt

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Mr. Ibraheem, in my experience with nitriding stainless steels, the diffusion zone IS the compound zone. Unlike nitriding alloy steel, the case in stainless is a discrete layer, with a definite layer thickness, rather than a continuous one wherein the nitrogen content merely drops off. Personally, I find this useful, as it avoids confusion as to whether we specified the total case depth or effective case depth. In stainless steels, they are the same!

Lee Gearhart
metallurgist - E. Aurora, New York
2004