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QPQ Salt Nitriding Question

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22 February 2010, 08:39
lawndart
QPQ Salt Nitriding Question
Is it possible to have an action treated this way? Has anyone had this done? Feedback?

Thank you,

LD


22 February 2010, 21:11
Doc224/375
I'm not a Smith so can't speak from that side of the equation !.


The wear resistance, corrosion resistance and hardness can be greatly increased by using low temperature QPQ salt-bath nitriding treatment. And it is a new strengthening method without distortion in the treating process. In this paper, 3Cr2W8V steel is dealt with QPQ salt-bath nitriding at 520°C, 540°C, 560°C and 2h, 4h, 6h, respectively. The treated surface microstructure was analyzed by using SEM. The depth of nitriding layer, scratch hardness and wear-resistance were tested for both QPQ salt-bath treated and untreated specimen. The corrosion resistance was tested in the 5%NaCl water by using spraying method. The experimental results indicate that a certain depth of white layer and diffusion layer of the steel can be obtained by using low temperature QPQ salt-bath nitriding treatment. The nitriding compound layer with high hardness, superior wear-resistance and stable microstructure can also be obtained on the surface of the parts. With increasing the temperature and the nitriding time, the depth of nitriding layer, scratch hardness and wear-resistance of 3Cr2W8V steel were greatly increased. Comparing with the untreated specimen, its hardness enhances 95.0%, wear resistance enhances 212.3%, anti-corrosion enhances 1288.9%. The experimental results show that the low temperature QPQ salt-bath nitriding treatment has many advantages, such as fast nitriding speed, uniform heating, short process time, low treating temperature, small distortion, high production rate, low cost, stable nitriding quality without pollution and so on.

John ; Fire off an E mail an ask them if it's doable .

http://www.burlingtoneng.com/salt_bath_nitriding.html

http://www.thermexmetal.com/liquid_nitriding.htm

http://www.ionic-tech.com/?gcl...G4hqACFQtfagodsHQMlw

archer archer archer
22 February 2010, 21:40
jimatcat
when tip burns www.canyonsportingarms.com built my .264 win mag m70 2 yrs ago, he suggested the QPQ coating/finish.... it's a dull black, very hard.... and nearly impossible to scratch..


go big or go home ........

DSC-- Life Member
NRA--Life member
DRSS--9.3x74 r Chapuis
22 February 2010, 21:51
butchlambert
Check with Joel Kendrick,joelkndrck@aol.com. He is a longtime friend, long range shooter, and an engineer that deals with QPQ and firearms. The process sure makes a barrel last longer and it is slick.
Butch
23 February 2010, 00:47
tiggertate
Yes, you can. Here is another one from Tip Burns; a SAKO in 300 WBY (the Talley bases were factory finished in these photos):






"Experience" is the only class you take where the exam comes before the lesson.
23 February 2010, 01:24
jørgen
We do use QPQ on quite some rifles, as a way better substitute for stainless.
The corosion resistance is many times better than the avarage "stainless", You can still use tough high strength CrMo steel for barrels with unsurpassed corosion, wear and scratch resistance.
On actions we use it in the same purpose , on a action that is already gasnitraded, for basic casehardness.

I would not recomend the process on "thermical" introduced casehardenings, or other thermical hardened parts, unless they originaly is anealed above 600 deg centigrades (apx 1230 deg F)
If used on parts anealed below this temperature, it might cause a to soft outer core, resulting in setback or cracking.

The reason that we dont use it on all our rifles, is that it is dificult to obtain a completly uniform black colour on large parts
23 February 2010, 06:38
30 Caliber Mag Fan
Friends-

Can QPQ be applied to Chrome Moly steel, as well or as easily as, Stainless steel?

Thanks in advance.


May the wind be in your face and the sun at your back.

P. Mark Stark
23 February 2010, 20:30
butchlambert
This is not a good photo, but if you polish your barrel it will look like a deep black polished finish.

Butch
28 February 2010, 05:25
lawndart
Thank you all.

It sounds perfect for a Sako or Win model 70 action, maybe not for a Mauser (except perhaps a VZ-24?).

I like chrome-moly barrels so much more than 416R that it borders on being unreasonable.

That is a very nice looking rig, Butch!

tiggertate, I recognize that carpet!

Doc, I have gotten some nice replies.

jA,gren, I will take the metal protection over cosmetics. I think that an aluminum Oxide blast or bead blast before finishing will make things more uniform looking at the end. What types of gas nitriding (nitrating?) do you have done to actions? Do those help with corrosion resistance, or is that more for appearance and smooth movement of the bolt inside the action?

Thanks again to everyone. It seems we are blessed by materials and applications developed for industry also helping our passion.

LD


28 February 2010, 23:44
jørgen
Hi Lawndart
Personaly i do agre to some extend, but as a manufactoring company, you have to look at what a customer thinks when he looks at your product, when it is displayed in a gunshop with no explanations. This is specialy important, if you want to be a mfg in mid/upper segment, where finish and feel is of importance (accuracy is an indiscussable must)

Our actions is basicaly not presurebearing, so the reason for the 30Hr gasnitrading is function and wearresistance, along with the capability to avoid dents and scratches. It is made of a medium carbon steel.
The bolt who is also treated the same way is a 42CrMo4 (4140) steel (prehardened to 29Hrc) this 30hr gasnitrading gives you a 0.02" surface of apx 650-700wikers (57-65HrC) on top of a werry tough core. The reason is Smoothness and wearresistance, as the bolt is high gloss vibrationpolished after gasnitration.

We have ben testing and trimming the QPQ process for years to get an acceptable and reliable look. This is for a "tool rifle" project
The most acceptable result we have obtained, by first a vibrationpolish in pretty smooth ceramic stones, folloved by asaltbathnitration, folloved by the oxidation process, folloved by another 20min vibrationpolish, folloved by a 2nd oxydation, ending vith a light cleanup.


One thing you must never ignore when applying a QPQ treatment to a termical hardened action, is the risk for heavy anealing, leaving you with way different strength, than original.

Best regards

Jørgen
10 March 2010, 04:09
lawndart
Jørgen,

How about a few pictures of the guns you build with the QPQ coating on the barrel and vapor deposition finish on the action?

That would be cool to see!!


10 March 2010, 17:50
buffalo
I have several rifles with QPQ treated barrels. Much superior finish than everything else regarding hardness and corrosion resistance..
I would personally hesitate to use it on an action because of many different parts with varying thickness - might cause some distortion/ warping..
On barrels the treatment just improve longevity and corrosionresistance above anything else..
My new 458AR will have a QPQ treated Border Barrel (cut rifle) and bottom metal will be QPQ treated as well. But the action will be parkerized...

And no - as far as I know you cannot QPQ treat normal stainless steel..
10 March 2010, 19:30
butchlambert
Buffalo, you can QPQ treat 416R stainless, but not participating hardness stainless.
Butch
10 March 2010, 19:36
buffalo
quote:
Originally posted by butchlambert:
Buffalo, you can QPQ treat 416R stainless, but not participating hardness stainless.
Butch


I stand corrected, thank you..
12 March 2010, 10:19
SWD
What does it cost to have a barrel QPQ Melonite treated?
12 March 2010, 21:02
butchlambert
SWD,
I posted Joel Kendricks email above. He can qutote you a price.
Butch