The microstructures evolution and composition shift of ZGCr30Ni20NRE steel at carburising atmosphere
by Xinmin Luo, Jinlan Wang, Kangmin Chen
International Journal of Microstructure and Materials Properties (IJMMP), Vol. 4, No. 4, 2009

Abstract: By means of scanning electronic microscopy (SEM), EDS and X-ray diffraction, the microstructures evolution and the composition shift of austenitic steel ZGCr30Ni20NRE at the carburising atmosphere were investigated. The experimental results showed that the continuous penetration of the active carbon atoms broke the thermodynamic equilibrium in the steel and caused the redistribution of the alloying elements. It is revealed that the chromium (Cr) content in M₇C₃ increased to 48.84%, whereas only 2.89% remained in austenite; and nickel (Ni) shifted into austenite to 41.67%, but 4.37% remained in carbide. This composition shift resulted in Cr dilution of the austenite, and the progressive growth of the M₇C₃ carbide, reaching over 50μm in diameter. The oxygen invasion in opposite direction resulted in the interior porous and the oxidised cavities. Consequently, it is most important for the radiant tube made of the steel to obtain anti-carburising on its outer surface and antioxidising performances on its inner surface respectively.

Online publication date: Tue, 02-Feb-2010

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Microstructure and Materials Properties (IJMMP):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com