Abstract
This paper present mathematical model which developed to predict the nitrided layer thickness (case depth) of gas nitrided and plasma nitrided austenitic stainless steel according to Fick's first law for pure iron by adapting and manipulating the Hosseini's model to fit the diffusion mechanism where nitrided structure formed by nitrided AISI 316L austenitic stainless steel. The mathematical model later tested against various actual gas nitriding and plasma nitriding experimental results with varying nitriding temperature and nitriding duration to see whether the model managed to successfully predict the nitrided layer thickness. This model predicted the coexistence of e-Fe2-3N and γ΄-Fe4N under the present nitriding process parameters. After the validation process, it is proven that the mathematical model managed to predict the nitrided layer growth of the gas nitrided and plasma nitrided of AISI 316L SS up to high degree of accuracy.
Highlights
This paper present mathematical model which developed to predict the nitrided layer thickness of gas nitrided and plasma nitrided austenitic stainless steel according to Fick’s first law for pure iron by adapting and manipulating the Hosseini’s model to fit the diffusion mechanism where nitrided structure formed by nitrided AISI 316L austenitic stainless steel
The mathematical model for total nitrided layer growth of austenitic stainless steel must account for the γ’ nitride thickness and ε-Fe2-3N layer thickness
The results of the comparison was very promising, especially in predicting the nitrided layer thickness of plasma nitrided AISI 316L SS. This is due to the fact that the mathematical model managed to predict the nitrided layer thickness of the plasma nitrided AISI 316L up to ± 8μm for plasma nitrided AISI 316L SS
Summary
This paper present mathematical model which developed to predict the nitrided layer thickness (case depth) of gas nitrided and plasma nitrided austenitic stainless steel according to Fick’s first law for pure iron by adapting and manipulating the Hosseini’s model to fit the diffusion mechanism where nitrided structure formed by nitrided AISI 316L austenitic stainless steel. Sensitization is occur where precipitation of chromium carbides (Cr23C6) forms at the grain boundaries, typically between 450 to 850oC; diffusional reaction in forming chromium nitride/carbide leads to the depletion of Cr in the austenitic solid solution and unable to produce Cr2O3 passive layer to make stainless feature. As a result, this phenomenon causes reduction in ductility, toughness and aqueous corrosion resistance [1].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
