Formation of Expanded Austenite Using Hybrid Low Temperature Thermochemical Heat Treatment on 2205 Duplex Stainless Steel

2014 ◽  
Vol 970 ◽  
pp. 244-247 ◽  
Author(s):  
Mohd Shahriman Adenan ◽  
M.N. Berhan ◽  
Esa Haruman
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Low Temperature ◽  
Duplex Stainless Steel ◽  
High Hardness ◽  
Hybrid Layer ◽  
Cross Sectional ◽  
Carbon And Nitrogen ◽  
2205 Duplex Stainless Steel ◽  
Expanded Austenite

Surface modification on 2205 duplex stainless steel (DSS) was performed by low temperature thermochemical hybrid (nitrocarburizing) heat treatment at temperature of 450° C and at holding time of 30 hours. During the process, carbon and nitrogen elements were simultaneously introduced onto the surface of DSS with composition of 5%CH4 + 25% NH3 + 70% N2. Microstructural observations reveal the formation of thick diffusional hybrid layer on the surface of 2205 DSS with very high hardness at cross sectional area. Both carbon and nitrogen diffusions formed expanded austenite (γN/C) and expanded ferrite (αC), however precipitation of nitride (Cr2N) which also occurred at the layer may deteriorate the corrosion resistance of 2205 DSS. Further investigation is required based on the parameters used in the process to produced precipitation free hybrid layer.

Surface modification of 2205 duplex stainless steel by low temperature salt bath nitrocarburizing at 430°C

2013 ◽  
Vol 271 ◽  
pp. 93-97 ◽  
Author(s):  
Runbo Huang ◽  
Jun Wang ◽  
Si Zhong ◽  
Mingxing Li ◽  
Ji Xiong ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Surface Modification ◽  
Low Temperature ◽  
Duplex Stainless Steel ◽  
Salt Bath ◽  
2205 Duplex Stainless Steel

scholarly journals Impacts of Stress Relief Treatments on Microstructure, Mechanical and Corrosion Properties of Metal Active-Gas Welding Joint of 2205 Duplex Stainless Steel

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4272
Author(s):  
Xiao-qin Zha ◽  
Yi Xiong ◽  
Tian Zhou ◽  
Yong-feng Ren ◽  
Peng-hui Hei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Welded Joints ◽  
Stress Relief ◽  
2205 Duplex Stainless Steel ◽  
Ultrasonic Peening ◽  
Stress Relieving

Stress relief treatments were carried out separately with a pneumatic chipping hammer, ultrasonic peening treatment, and heat treatment for metal active-gas welding (MAG) welded joints of 2205 duplex stainless steel. The effects of these methods on the residual stress, microstructure, mechanical properties and corrosion resistance of welded joints were studied. Results show the stress state of the weld and the surrounding area was effectively improved by the pneumatic chipping hammer and ultrasonic peening treatment, and the residual stress field of the surface layer changed from tensile stress to compressive stress. On the contrary, low-temperature stress relieving annealing had no obvious effect on stress distribution. After the pneumatic chipping hammer and ultrasonic peening treatment, the welded joints were machined and hardened. Correspondingly, strength and hardness were improved. However, the heat treatment only led to a slight decrease in strength and hardness due to the static recovery of the welded joint structure. All stress relief methods effectively improved the corrosion resistance of welded joints, with the ultrasonic peening treatment giving the best performance.

scholarly journals Low temperature plasma carburizing of AISI 316L austenitic stainless steel and AISI F51 duplex stainless steel

2013 ◽  
Vol 66 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Carlos Eduardo Pinedo ◽  
André Paulo Tschiptschin
Keyword(s):  
Stainless Steel ◽  
Low Temperature ◽  
Duplex Stainless Steel ◽  
Aisi 316L ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Carbon Carrier ◽  
316L Austenitic Stainless Steel ◽  
Expanded Austenite ◽  
Plasma Carburizing

In this work an austenitic AISI 316L and a duplex AISI F51 (EN 1.4462) stainless steel were DC-Plasma carburized at 480ºC, using CH4 as carbon carrier gas. For the austenitic AISI 316L stainless steel, low temperature plasma carburizing induced a strong carbon supersaturation in the austenitic lattice and the formation of carbon expanded austenite (γC) without any precipitation of carbides. The hardness of the carburized AISI 316L steel reached a maximum of 1000 HV due to ∼13 at% carbon supersaturation and expansion of the FCC lattice. For the duplex stainless steel AISI F51, the austenitic grains transformed to carbon expanded austenite (γC), the ferritic grains transformed to carbon expanded ferrite (αC) and M23C6 type carbides precipitated in the nitrided case. Hardness of the carburized case of the F51 duplex steel reached 1600 HV due to the combined effects of austenite and ferrite lattice expansion with a fine and dispersed precipitation of M23C6 carbides.

Low-Temperature Nitridation of 2205 Duplex Stainless Steel

2019 ◽  
Vol 51 (2) ◽  
pp. 608-617 ◽  
Author(s):  
J. C. Dalton ◽  
F. Ernst ◽  
A. H. Heuer
Keyword(s):  
Stainless Steel ◽  
Low Temperature ◽  
Duplex Stainless Steel ◽  
2205 Duplex Stainless Steel

Surface Modification of 2205 Duplex Stainless Steel by Low Temperature Thermochemical Hybrid Heat Treatment at 450° C

2013 ◽  
Vol 845 ◽  
pp. 408-411
Author(s):  
M.S. Adenan ◽  
M.N. Berhan ◽  
E. Haruman
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Low Temperature ◽  
Duplex Stainless Steel ◽  
Treatment Process ◽  
Surface Hardness ◽  
Horizontal Tube ◽  
Holding Time ◽  
Hardness Profile ◽  
Heat Treatment Process

An approach has been made in developing hybrid heat treatment process for improvement of surface properties of duplex stainless steel (DSS). The process was performed using horizontal tube furnace at temperature of 450° C at holding time of 4, 8, 16 and 30 hours. Carbon and nitrogen elements were simultaneously introduced onto the surface of DSS with a ratio of 5% CH4 + 25% NH3 + 70% N2. The microstructure, phase analysis, surface hardness and hardness profile were systematically assessed. Hybrid heat treatment process managed to produce diffusional layer, where longer holding time had increased the thickness of the layer and improved the surface hardness. Expanded austenite phase has been formed at specimens 8, 16 and 30 hours. Longer holding time however gradually diffused Cr2N at the ferrite grains at the substrates. From the process, it can be concluded that low temperature hybrid heat treatment be able to improve the surface hardness of DSS however concern on holding time must be highly considered.

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