Structure of Nitrided Layer Formed on Austenitic Stainless Steel by a New Gas Nitriding Process

2008 ◽  
pp. 245-249
Author(s):  
Hisao Fujikawa ◽  
Takanori Watanabe
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Nitrided Layer ◽  
Nitriding Process ◽  
Gas Nitriding

scholarly journals The influence of laser re-melting on microstructure and hardness of gas-nitrided steel

2016 ◽  
Vol 36 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Dominika Panfil ◽  
Piotr Wach ◽  
Michał Kulka ◽  
Jerzy Michalski
Keyword(s):  
Laser Beam ◽  
Laser Treatment ◽  
Diffusion Zone ◽  
Nitrided Layer ◽  
Nitriding Process ◽  
Beam Power ◽  
Gas Nitriding ◽  
Nitrided Steel ◽  
Laser Beam Power ◽  
And Diffusion

Abstract In this paper, modification of nitrided layer by laser re-melting was presented. The nitriding process has many advantageous properties. Controlled gas nitriding was carried out on 42CrMo4 steel. As a consequence of this process, ε+γ’ compound zone and diffusion zone were produced at the surface. Next, the nitrided layer was laser remelted using TRUMPF TLF 2600 Turbo CO2 laser. Laser tracks were arranged as single tracks with the use of various laser beam powers (P), ranging from 0.39 to 1.04 kW. The effects of laser beam power on the microstructure, dimensions of laser tracks and hardness profiles were analyzed. Laser treatment caused the decomposition of continuous compound zone at the surface and an increase in hardness of previously nitrided layer because of the appearance of martensite in re-melted and heat-affected zones

Low Temperature Fluidized Bed Nitriding of Austenitic Stainless Steel

2006 ◽  
Vol 118 ◽  
pp. 125-130 ◽  
Author(s):  
E. Haruman ◽  
Y. Sun ◽  
H. Malik ◽  
Agus Geter E. Sutjipto ◽  
S. Mridha ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Fluidized Bed ◽  
Corrosion Behaviour ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Temperature Plasma ◽  
316L Austenitic Stainless Steel ◽  
Fluidized Bed Process

In the present investigation, low temperature nitriding has been attempted on AISI 316L austenitic stainless steel by using a laboratory fluidized bed furnace. The nitriding was performed in temperature range between 400°C and 500°C. X-ray diffraction, metallography, and corrosion tests were used to characterize the resultant nitrided surface and layers. The results showed that fluidized bed process can be used to produce a precipitation-free nitrided layer characterized by the S phase or expanded austenite on austenitic stainless steel at temperatures below 500°C. But there exists a critical temperature and an incubation time for effective nitriding, below which nitriding is ineffective. The corrosion behaviour of the as-nitrided surfaces is significantly different from that previously reported for low temperature plasma nitriding. This anomaly is explained by the formation of iron oxide products and surface contamination during the fluidized process.

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