I know that heat treating mausers on this site has been been analyzed to death, but I ran across this on a heat treater's site and thought it interesting.



[Peters' Heat Treating, Inc. offers state of the art Nitreg® Controlled Gas Nitriding. The Nitreg® gas nitriding process can be applied to practically any grade of structural steel, many tool steel grades, and cast iron.

Nitriding is a highly specialized surface hardening treatment that produces a thin but high hardness case on a wide variety of steels. The significant advantage of nitriding over other surface hardening processes is that the case hardness is developed without quenching and subsequent distortion issues. Finishing operations can be eliminated or minimized.

The following list indicates steel grades that have been successfully processed in industrial conditions and field tested with favorable results.

Nitriding Steel: Nitralloy 135M, Nitralloy N and equivalents
High Speed Steels: AISI M2, M36, M42
Tool Steels: D2, H11, H13, A10, A2, S7
Carbon Steels: 1045, 1008, 1010, 1020, 1060
Alloy Steels: 4130, 4140, 4330V, 4340, 5130, 5140, 8620, and 9310
Cast Irons: Ductile, Grey
Nitride surfaces are extremely wear resistant and provide anti-galling properties. Nitriding also produces extended fatigue life and improves corrosion resistance. Other advantages include resistance to softening by temperatures up to the processing temperature (approximately 950F-1025F). Many of our customers have chosen Nitreg® as a replacement for carburizing, ion nitriding or salt bath nitriding, enjoying the invaluable benefits of no distortion and the elimination of costly finish grinding.

Typical applications include stampings, forgings, castings and machined components used in machinery, defense, aerospace, automotive, tool & die, oil drilling and mining.}

Kevin,

I agree, interesting and will check the company's web site assuming they have one. This process could be a great find if within financial reach. I especially like the benefit of lack of distortion and re grinding.

Thanks,

Stephen

D.S.A. arms is using nitriding on their AR-15 barrels instead of hard chroming the bores. Not as tough as chrome, but it has some wear benefits. Nitriding has been used for surface hardening of crankshafts longer than I have been alive and now the camshaft companies are going to it in an attempt to get flat tappet cams to live with the newer low zinc/phos oils. From what I recall it is usually done to about a depth of .003. What application are you thinking of using this on?

quote:

Originally posted by lee440:
What application are you thinking of using this on?

Mauser actions!

The company that I work for uses this on H13 and S7 insers that are in high wear situations with injection molds.

I have seen it in two colors gold and natural/silver I duobt that the surface will take blue.

BTW it's not cheap and is done at about 750 deg.

Peters'HT is an excellent company ,very reliable !
It's one of the best for custom knife HT ,in fact my last custom had their HT. The knife was made of CPM 3V a very tough steel for choppers etc .

The CPM family of steel is tough stuff for sure.

Ted you guys grind your own check rings?? Is that because the can't get the flow with an off the shelf ring? Or is your shops labor that cheep due to being set up to do it?

We use to buy all our stuff off the shelf from Sante fe Machine works or get OEM from Toyo or Toshiba.

I'll note that this is based only on my experience with basic nitriding and carbo-nitriding of steel parts (shafts, gears, and tooling). There are more advanced processes that I am not familiar with.

There are a couple of factors that make nitriding a poor choice for a firearms reciever/bolt. First, the processing temperatures are low and within a range that will anneal the underlying base metal. This means that while the surface is being hardened, the core is being softened. This is not the direction you want to go.

The other issue is that the newly hardened surface cannot be altered by reheating to "temper" it. This makes it both hard and somewhat brittle (thin layers, 0.005" or so,won't act brittly, but thick layers, >0.10" will chip under impact loading).

Carburizing as it was originally used, and is used today allows the maker to impart not only a hard, wear resistant surface, but also a tough surface and core. And, through further heating and cooling cycles the maker can really dial in what they want. The processing temps are higher and in a range where manupulation of the underlying microstructure (ferrite, pearlite, martensite) is possible.

JRC

quote:

Originally posted by kcstott:
Ted you guys grind your own check rings?? Is that because the can't get the flow with an off the shelf ring? Or is your shops labor that cheep due to being set up to do it?

We use to buy all our stuff off the shelf from Sante fe Machine works or get OEM from Toyo or Toshiba.

On our big stuff 500 tons up to 1K we re-grind them as the maint. dept sees a need to....Our shop labor is not figured into in-house repair of machinery.

Did you cary stock or order these parts NDA?

We had one extra set screw tip, check ring, and seat for each machine and few of the more critical machines we had a spare screw as well. Keep in mind we never had a specialized screw which we did need for a few machines. Management was to cheep to do it. So we had GP screws for everything.
Ours ran from 90 to 950 ton including an all electric Toshiba 500 ton machine. And they wondered why the scraped so much plastic