Download presentation
Published byPatrick Yongue Modified over 11 years ago
1
Modern Methods of Ferritic Nitrocarburizing (FNC)
H-13 section 28” dia 48” depth V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec open basket Open bed at temperature Loaded basket, ready for carousel Removal from fluidized quench
2
Ferritic Nitrocarburizing (FNC) How we got here
1900’s – Dr. Adolph Fry Discovered that Nitrogen and Iron had affinity to one another. Developed nitrogen iron equilibrium table Nitralloy steels Studied effect of adding other alloys Vanadium, Tungsten, Manganese, Molybdenum, Titanium V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
3
Ferritic Nitrocarburizing (FNC) Continued 2
1900’s Adolph Machlet – New Jersey American Gas Company - Elizabeth Applied for patents which were received June 24, 1913 US saw no commercial benefit at the time V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
4
Ferritic Nitrocarburizing (FNC) Continued 3
1927 Pierre Aubert – Chicago At SME convention presented research for practical applications in Europe Included railway steel, machine tools, auto, aviation. Benefits – hard surface, core not changed, high wear, unaffected by temper, corrosion resistance. V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
5
Ferritic Nitrocarburizing (FNC) Continued 4
1928 – McQuaid and Ketchum Timken – Detroit Axle Co. Metallurgists – practical applications Used work of Fry and Machlet as pivot point 1929 – Robert Sergeson Central Alloy Steel – Canton, OH Varying Al content in nitro alloy steel with effect of nickel V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
6
Ferritic Nitrocarburizing (FNC) Others
V. O. Homberg & J.P. Walsted - MIT Effect of varying temperature – white layer Equipment preheat and decarburization effect Dr. Carl F. Floe – Assoc MIT Continued study of white (epsilon) layer The Flow Process – methods to change compound layer Eventually this research lead to “Ion Nitriding” – in effort to shorten cycle times, reduce distortion, and improve metallurgical properties. V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
7
Types of Nitriding Fluidized Bed Nitriding and FNC Nitempering
Controlled Nitrocarburizing Soft Nitriding Triniding Nitroc Process Vacuum Nitrocarburizing Nitrotec Process Austenite Nitrocarburizing V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
8
FNC – Thermochemical Diffusion
Process where N2,C, and sometimes a very small degree of O2 atoms are diffused into the surface of a ferrous substrate forming a compound layer and subsurface diffusion layer. Done in relatively short period of time at sub critical steel temperatures Wear properties, Corrosion (solder), and improved fatigue resistance. V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
9
Prominent Developments FNC
Salt Bath Nitrocarburizing Started about 55 years ago commercially. 1959 – Germany patented Tuffride 1970’s – EPA regs prohibiting cyanide base materials Tufftride replaced with Melonite and French process called Sur-sulf These two processes still in use today. V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
10
Prominent Developments FNC Continued
Gas – Originally patented in 1961 by Joseph Lucas Industries Ltd. 1965 – B. Presnosil Published results of study doing Gas. During following quarter of a century – developed Triniding (NH3 and exothermic gas), Nitemper, Lindure and a two stage process (Deganit) from Germany V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
11
Fluidized (FNC) Bed Phenomenon
An 1879 patent discusses baking minerals under fluidized bed conditions Bed of finely-divided heated particles, usually Aluminum oxide made to behave like a liquid by moving exothermic and reactive gases through the medium Smooth or bubbly properties – determines fluidization quality. Size and hetrogeneity (other offspring) of bubbles – influences rate of the solid mixing Bed geometry, gas flow rate, type of gas distributor Vessel features – baffles, screens, heat exchangers V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
12
Analogy of Fluidized Bed and Liquids
Plunging your hand into a fluidized bed (unheated of course) gives the sensation of placing your hand in a bucket of water. Light objects introduced in the bed will float if light enough. Behaving as a liquid causes the entire introduced object (metal) to be in complete contact with the aluminum oxide separated by the reactive gas/gases that surround the media and cause diffusion and white layer creation. The heat from the bed starts the diffusion V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
13
Fluidized (FNC) Heat Transfer Factors
Cleanliness of tool steel Mild to aggressive alkaline bath at elevated temperature – bed & part contamination Particle diameter – influences heat transfer In practice 100 micro mm (.3940 micro inches) Bed material density Optimum value kg/cu m or lb/cu. ft. Fluidized velocity of gas/gases V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
14
Optimizing heat transfer to bed
Optimizing gas/gases flow rate Between 2 to 3 times the minimum fluidization velocity Curve peaking To high – particle entrapment – high gas consumption To low - poor heat transfer – lack of uniformity Bed screws do not provide consistency V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
15
Relationship of gas fluidization velocity to heat transfer rate
Heat transfer rate falls off rapidly V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
16
Relationship of Bed Temperature to necessary Flow Rate
Higher bed temperatures require less gas flow V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
17
Objective to get maximum heat transfer to part and optimize velocity of the gas/gases
Heat transfer rate falls off rapidly without optimized gas flow rate Higher bed temperatures require less gas flow V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
18
Now a better way to attain repeatability - flow and heat
Computer control and automation Adjustable ceramic screens Eclipse valves with flow meters Sensor feedback to computer controls and automation system V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec First Fully Automated System in the United States and Canada
19
H-13 after only 2 hours in bed (N2,NH3,CH4)
Vickers hardness from surface V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec Compound layer 5-20 microns = inches Diffusion layer microns = inches
20
Future Uses of Fluidized Beds
Development of Hard PVD (below 700o F) thermochemical surface treatments in Australia – grant by IR & D board Coatings such as vanadium carbonitride, and chromium carbonitride at low temperature by diffusion-based treatments Patents already applied for and equipment available to perform new range of low temperature surface treatments – Qab. V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
21
Nitrogen and Alloy based below 700o C Carbon based above 700o C
Range of coatings - QAB Courtesy of QHT Ray Reynoldson Nitrogen Based Nitriding Ferritic Austenitic Alloy Based Chromium Vanadium Titanium Niobium Carbon Based Carburizing CD Carburizing Carbonitriding V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec Nitrogen and Alloy based below 700o C Carbon based above 700o C
22
Process to form CrCN - QAB
Courtesy of QHT Ray Reynoldson V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec Aluminum Oxide media to obtain CrCN is coated
23
Qab Profile for CrCN and Nitrocarburized structure
Hardness Profile - QAB Courtesy of QHT Ray Reynoldson Thickness controlled by time of processing CrCN = 1550v NitroC = 950v V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec Qab Profile for CrCN and Nitrocarburized structure
24
Distribution of Elements in White Layer
Courtesy of QHT Ray Reynoldson Thickness controlled by time of processing CrCN = 1550v NitroC = 950v V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec % of Cr highest near surface
25
Field test results CrCN
Courtesy of QHT Ray Reynoldson V Notch Charpy testing of incoming H-13 should show a minimum of 8 ft. lbs according to NADCA spec
26
Badger Metal Tech, Inc. 262-252-3956 Toll Free 800-366-1973
TOOLING CIRCLE OF LIFE TOOLING CYCLE OF LIFE Want more information regarding our capabilities regarding fluidized bed treatments? Visit our website and click on the flame logo at the top of our home page For more detailed information on our process, we encourage you to visit our web site: Over 104 pages of information, photos, curves, FAQ’s, testimonies of our customers, and past issues of our newsletter are posted and kept current. Badger Metal Tech, Inc Toll Free
Similar presentations
© 2025 SlidePlayer.com Inc.
All rights reserved.