White Paper - Gas Nitriding Furnaces

Gas Nitriding Furnaces
SECO/WARWICK offers various furnace styles in Batch and
Continuous for Gas Nitriding. SECO/WARWICK is a technology
leader with the proprietary ZeroFlow® method of economical gas
flow control.
Listed below are all the options of SECO/WARWICK furnace styles
for gas nitriding. Equipment can achieve optimum results with gas
nitriding using uniform, high convection heating, precision nitriding
potential and ammonia control along with extensive experience
with load mechanics and processing of various metals.
Experienced SECO/WARWICK process specialists can assist in
VTR Vacuum Retort Tempering Furnace
furnace type selection and in product material handling/loading.
The SECO/WARWICK R&D facilities help customers in determining the correct cycle for their products. Optional
tools such as a simulation and database programs for many common alloys and case requirements can help
pinpoint potential cycles quickly.
Why SECO/WARWICK?
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Experience
Most Advanced Technology
R&D assistance
Value
Global Resources
In addition to Gas Nitriding, Ferritic NitroCarburizing is a related nitriding process which is gaining much popularity
due to the specific wear and anti-corrosion properties offered, including coupling with post-process high
temperature oxidation.
Equipment Styles Best Suited for Nitriding and NitroCarburizing
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Pit Retort Furnace
Horizontal Front Loading Retort Furnace
Bell Retort Furnace
Roller Hearth Multi-Chamber
Accessories
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Vacuum Purge
Turbo Atmosphere Cooler
Various Controls Options
Emissions Burning
Pit Furnaces are an ideal choice for
nitriding applications
www.secowarwick.com
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Gas Nitriding
) NH3 w
-1/2
Np (atm
700
1,5
600
NH3
log (Np) (atm
-1/2
)
1
550
500
450
o
400
C
N2
10,00%N
ε
9,75
9,50
9,25
9,00
8,75
8,50
Fe-N
0,5
5,897
5,89
8,25
0
5,87 %N
γ'
NH3 w
NH3/H2 NH3/NH3 zdys.
31,6
91
88
17,8
87
83
10,0
81
76
5,6
74
67
3,2
65
58
1,8
55
46
1,0
43
34
0,3
21
15
0,1
8,7
6
0,03
2,9
1,9
5,85
5,82
-0,5
5,78
5,73
-1
α
0,07
γ
0,01
0,005
0,05
0,001
0,03%N
-1,5
1,0
1,1
1,2
1,3
1,4
1,5
-3
x10
1/K
T - Np Diagram (Lehrer, 1936) ( Np – T – [N]Fe )
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For more information or to request a quote, e-mail info@secowarwick.com
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Gas Nitriding
ZeroFlow Control by SECO/WARWICK
Decades of gas nitriding experience came with the realization that and large volume of process gas was required
and that better options must be available that can accomplish two things:
1.
2.
Proper formation and control of the nitrided layer,
By reducing the volume of process gas, you can reduce the need for large storage of ammonia and
nitrogen.
Does nitriding with the use of ZeroFlow control obtain the same results as other nitriding methods?
Definitely yes. It is nitriding, based on continuous adjustment of the nitriding potential, which assures obtaining
the proper structure of nitrided layers and offers the same results as in other nitriding methods. It has been
confirmed in many industrial applications.
Does use of ZeroFlow control allow for nitriding without creating the white layer of nitrides?
Definitely yes. That method, through proper adjustment of the nitriding potential, allows for nitriding without
creating the white layer. In many cases a white layer might be desired and is still controllable.
Is it possible to adapt your existing furnaces with the ZeroFlow nitriding method?
Definitely yes. In many nitriding furnaces there is no proper automatic atmosphere adjustment, or the processing
costs are high with gases and royalties. Under ZeroFlow the gas system will be simplified, and the ZeroFlow control
does not always require using materials with the very highest content of expensive nickel on the internal
equipment surfaces.
What practical benefits are offered by ZeroFlow control in relation to other methods?
The ZeroFlow option reduces operating costs and offers improved quality of the resulting nitrided layers.
www.secowarwick.com
For more information or to request a quote, e-mail info@secowarwick.com
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Gas Nitriding
Industrial Services
A wide range of services are available for our equipment. These include rebuild projects, field service, spare parts,
equipment supply, control and combustion upgrades, and fabrication services. As a result of these services, we
have provided our customers improved performance, lower emissions, better efficiency and enhanced product
temperature uniformity.
About SECO/WARWICK
The SECO/WARWICK Group is one of the world’s leading manufacturers of heat treatment furnaces and a
technology leader. With our fully equipped research and development facility and cooperation with the leading
academic centers in Europe, we are able to provide innovative solutions not offered anywhere else in the world.
The Group is made up of companies located in five countries on three continents, and we sell our products in 45
countries around the world. We supply furnaces to customers involved with steel, titanium and aluminum
production as well as aluminum recycling, forging, automotive, aerospace, commercial heat treating, HVAC/R,
electronics, wind energy, medical equipment and nuclear industries. Visit our website below for more
information.
The latest design, materials, and equipment specifications should be obtained from the company before any
reliance is placed on this standard bulletin since changes may occur due to product improvement.
www.secowarwick.com
For more information or to request a quote, e-mail info@secowarwick.com
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