Nitriding tool steels and stainless steels

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Tehemton

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Hi,
I came across a process known as nitriding which case hardens steels. And some places mentioned that it essentially doubles the surface hardness of some steels like tool steels, which made me curious if anyone has tried nitriding knife steels and if yes, how the knives perform?
 
Nitriding is a process where a thin deposit of nitrogen is diffused into the surface of steel to increase wear. It is done on softer things usually, but also on hard steel. It makes a smooth and low friction surface. Drill bits and cam shafts are two examples. On a knife, low friction on the bevels would do little to make it cut better. Knife blades are already at very high hardness. The edge is thin, and sharpening would immediately remove any deposit there ... so it is of no use on a knife as far as sharpness and hardness. It is used to make things like the bearing area and locks on folders have lower friction and longer wear.

Carbonitriding is a similar and better process where both carbon and nitrogen are added to the steel surface. This is done to make mechanical parts stronger, but still of no real use on knife blades.

Specialty "blades" like ones used in industry to cut all day long on paper cutters or other industrial cutting may be nitride coated to reduce friction and heat .... but not for sharpness.

Carbidizing is an application of tungsten carbide ( occasionally titanium carbide) along the bevel at the edge of a knife. The edge wears, exposing the thin very hard layer as the cutting edge. Some like this and some don't, but it is no replacement for a fine slicing edge.
 
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Nitride, Melonite, Tennifer treatments..... ALL the same thing! They are different names for Ferritic Nitrocarburizing. And as Stacey said, it is used to case harden typically "softer" metals to improve wear. And it leaves the surface very slick. You can have it done in any color, as long as its BLACK! Again as Stacey pointed out, it would be futile on the edge, as it would be removed upon sharpening. Nitrocarburizing is not a coating, rather it is a surface treatment that reaches approx .003" into the metal. I use Nitride treated parts in almost all of my gun builds. My AR-15 builds sport barrels & every gas system/charging-cycling component with Nitride treatment. It is much older than most people know. It was made famous by Glock and their "Tennifer" treatment of barrels & slides. I, as many other knifemakers, would not use it on my knives, for fear of disturbing the heat treatment we strive for.
 
Nitriding can be done in different colors-gold (titanium nitriding,) for example.
Some versions require too much heat for a knife blade-others are fine.
Nitriding is a good surface finish for carbon steels to keep corrosion at bay.
 
I used to work for a company that made, among other things, sheet metal screws. These screws were CarboNitrided to a depth of .003". It was called case hardening. The idea was to have a screw that was hard enough on the outside to make a female thread in sheet metal but have a ductile core so the screw would not snap off when torqued. The process was done in a long rotary drum furnace with a controlled atmosphere, and spiral baffles moved the screws through the furnace.
 
Bill DeShivs said:
Nitriding can be done in different colors-gold (titanium nitriding,) for example.
Some versions require too much heat for a knife blade-others are fine.
Nitriding is a good surface finish for carbon steels to keep corrosion at bay.
Click to expand...


Uhhhhh, NO! Absolutely, inherently WRONG!

Titanium Nitride is simply a name. It's actually CERAMIC COATING! And has nothing to do with Ferritic Nitrocarburizing! Which, like I said, is going to be BLACK! It is not a coating! It is a metal treatment. It also works fantastic on stainless steel. Not just carbon. Next time read some more before posting.
 
As it was explained to me by Chad Buie at Club Custom Guns-who has done nitriding on knife blades for me, gold nitriding can be done.
While Wikipedia says that TiNi is a ceramic, they are wrong. TiNi is a METALLIC compound.
I can tell you that my titanium nitrided, gold colored drill bits shure don't have a ceramic coating!
Glock's nitriding has no color at all. The guns are colored after the nitriding.
Ferric nitrocarburization may be a different process. I am speaking of PVD processes.
 
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Glock has always used Ferritic Nitrocarburizing. They named it TENNIFER treatment. There is no "coloring" afterwards. Again, black is the only color.

PVD was not the topic of this thread. Bill brought it up by incorrectly confusing Nitride QPQ with TiN. But allow me to educate you. Saying the PVD process TiN is a "ceramic" coating IS a correct statement. The definition of a ceramic coating is an inorganic, nonmetallic solid comprising metal, nonmetal or metalloid atoms primarily held in ionic and covalent bonds. It can have highly oriented to semi-crystalline form. Of course it is not our basic understanding of ceramic, say for instance a sharpening stone. But it is not metal.

Now, back to topic. The OP was asking about Nitriding QPQ. So to Tehemton, both Stacey and my answers to you were correct ones.
 
Thanks guys.
Yeah I guess it would only help in terms of abrasion resistance and reduce friction. Wouldn't help in terms of edge holding in any way.
 
I do not think that TiNi (Titanium Nickel) is a Physical Vapor Deposited coating. Titanium Nitride (TiN) is a ceramic coat that is applied by the PVD process.
I have some TiN coated Buck blades that are chisel sharpened (single bevel) to expose the TiN on the micro edge. This edge is very wear resistant (82 HRC). It is also self sharpening as the blade steel wears away in preference to the harder coat making the TiN stand prouder. Buck called this line of blades BuckCote or Ion Fusion. They also produced these blades using other ceramics such as ZrN, TiCN, and TiAlN.
I have TiN coated drill bits and tool bits which are PVD coated after they are sharpened which greatly increases the wear resistance (tool life).
 
DavidHoback said:
Uhhhhh, NO! Absolutely, inherently WRONG!

Titanium Nitride is simply a name. It's actually CERAMIC COATING! And has nothing to do with Ferritic Nitrocarburizing! Which, like I said, is going to be BLACK! It is not a coating! It is a metal treatment. It also works fantastic on stainless steel. Not just carbon. Next time read some more before posting.
Click to expand...

Next time get a decent personality before posting!!! No reason the be a jack a$$!!!
 
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I think that this kind of link is alowed ?
http://www.plasma.com.mk/images/stories/downloads/TECHNICAL_MANUAL_FOR_PLASMA_NITRIDING.pdf

http://www.plasma.com.mk/images/stories/downloads/PLASMA_NITRIDABLE_STEELS_TABLE 1.pdf


http://www.plasma.com.mk/images/stories/downloads/PLASMA_NITRIDABLE_STEELS_TABLE 2.pdf

Tehemton said:
Thanks guys.
Yeah I guess it would only help in terms of abrasion resistance and reduce friction. Wouldn't help in terms of edge holding in any way.
Click to expand...
It would help in terms of edge holding . . .. . .. But be aware that not any steel can be nitrided ...temperature is high in process of nitriding ...Look in link I posted
 
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Is there an echo in here? LOL.

I did mention that most knifemakers won't use it because of fear of damaging the heat treat.

Also, TiNi is not Titanium Nickel. Titanium Nickel is not even any kind of coating. It's an allow of the two. Or, titanium can be Nickel PLATED. You are correct in that Nickel Plating is not a PVD(you could have just said PVD. You didn't have to Google what it stands for and type in the three words but it's ok. I search things all the time.)

TiNi, or TiN stands for Titanium Nitride. And again, the OP was asking about Nitriding, which by itself is a term used for Ferritic Carburizing. All of the PVD's & Nitriding would increase edge retention....until it needs sharpened. And then it would be lost. It's just not cost effective.

There is a reason I know this guys. And you can fail at arguing or call me names...but the facts can not be refuted
 
OK, lets all chill. I think the basic question has been answered. I'll close the thread.
 
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