Stainless and blued on parts on the same rifle?

[eeckle]

Hi,

Is there any problem with combining blued and stainless parts on the same rifle?

Screwing a stainless barrel into a blued action? Or stainless trigger guard on blued action? Whatever combo?

Is there something about where the different metals contact they corrode faster or something?

[MeccaOz]

Im not a guru by any stretch and can only repeat what I have seen, but I do know guys who have replaced their barrels with stainless when they were originally blued, and after years of work they dont seem to suffer. Ive olso noticed most ruger rifles in there standard line have stainless bolts on blued actions.

[1290]

Different elements/metals do have different galvanic potentials, where 1 will corrode preferentially to the other, but the alloys of iron used in firearms Carbon/Chromium/Molybdenum/Manganese etc would probably have too close a potential to create an issue unless they were bathed in an electrolyte (say salty water)

The thermal properties are more the issue, hence dont mix Aluminium parts (not even rails!) with steel...

[DaleH]

Generally if you have stainless in contact with iron you will get galvanic corrosion (the same process as galvanising steel with zinc - the zinc is more reactive than steel and therefore corrodes in preference to the steel) - this is particularly evident with normal mild steel and stainless steels. It is good engineering practice to avoid the contact between two dissimilar metals in the general environment. As 1290 alludes to, the there may not be such a big difference of galvanic potential between the grades of steel and stainless used on gun barrels for corrosion to be evident in normal use. The exclusion of oxygen, water etc from the parts as practiced by every responsible gun owner (by cleaning and lubricating etc) and the blued coating on steel rifle parts should be sufficient to minimise the potential for the corrosion.

[meek]

I don't know if they're doing anything special, but Colt do this with they factory rifle the M2012 Manners Tactical.

Stainless barrel, blued everything else.



(credit to on_one_wheel for linking in another topic)

[1290]

thats definitely going to dissolve away at its first outing....

What alloy is the blued? maybe its also stainless

[meek]

Do I have that wrong? I didn't think you could blue stainless?

You know, because it's 'stainless'

I'm just going by pictures here so...

[Seconds]

For the Colt I think you're right.

They make a big deal over the barrel for this one.

"Match-grade stainless steel custom spiral fluted 22" barrel designed by E.R Shaw Inc, 6-groove button rifled, 1:10 twist"

Other than that the rest is regular old blued?

[The Brass]

Do I have that wrong? I didn't think you could blue stainless?

You can, but it needs to be heated in a particular formula to 'stick'.

It's not just a plain cold dip'n'stain like mild steel.

Google 'hot bluing' for it.

[1290]

You can passivate (I think thats the correct word) or 'blue' practically any alloy of Iron, depending on the make up of the alloy, it will result in different shades of blue.... or red or purple or orange, etc - blue is only the most popular surface treatment. Depends on the mixture of chemicals in the 'bluing' solution

Stainless doesnt always have to look silvery grey and Chrome steel shiny...

[MeccaOz]

You can passivate (I think thats the correct word) or 'blue' practically any alloy of Iron, depending on the make up of the alloy, it will result in different shades of blue.... or red or purple or orange, etc - blue is only the most popular surface treatment. Depends on the mixture of chemicals in the 'bluing' solution

Stainless doesnt always have to look silvery grey and Chrome steel shiny...

I could have a red blued barrel ? LOL.... Seriously I NEED one I think ...

[1290]

You can passivate (I think thats the correct word) or 'blue' practically any alloy of Iron, depending on the make up of the alloy, it will result in different shades of blue.... or red or purple or orange, etc - blue is only the most popular surface treatment. Depends on the mixture of chemicals in the 'bluing' solution

Stainless doesnt always have to look silvery grey and Chrome steel shiny...

I could have a red blued barrel ? LOL.... Seriously I NEED one I think ...

Its passivation, making the steel 'passive', referred to as bluing only because blue is the most common or 'normal' colour finish...

[hrrl]

it will result in different shades of blue.... or red or purple or orange, etc - blue is only the most popular surface treatment. Depends on the mixture of chemicals in the 'bluing' solution

Purple? Pimping

[Die Judicii]

Hi,
The very original "Blued" metal was achieved by machining/polishing the part, and then carefully heating uniformly to a temperature just below the point where mill scale starts to form, and then quenching in Kerosene.
The old "Power Kero" was the best, and generally gave a much richer colour than ordinary kero.
Done at the precise temp, it resulted in a beautiful deep rich blue with a flawless surface.

As for dissimilar metals in contact causing corrosion, 316 Stainless is neutral, and can be in contact with other metals including aluminium without any problem.

Ferrous metals can be attached to aluminium with little or no galvanic corrosion, as long as there is a neutral barrier in between such as Duct Tape in between Aluminium cladding and the ferrous metal it is attached to.

It is also a fallacy that "Stainless Steel" is,,, stainless.
When stainless is bolted to ferrous steel, and the ferrous steel starts to rust, it will actually stain the Stainless

When welding Stainless to Ferrous, you will eventually have weld failure beginning at the root of the weld,, unless a specific electrode that is intended for dissimilar metals is used.

[1290]

you're thinking about colour case-hardening.... not bluing...

Stainless steel is not ferrous you say?

[on_one_wheel]

That's why they call it stainless, not stainproof.

I've seen stainless rust like mild steel, I'm talking rusted away.... gone, in a very acidic steel pickling plant.

I have even seen rust spots on a mates stainless rifle barrel.

[on_one_wheel]

Ferrous / non-ferrous

[Die Judicii]

That's why they call it stainless, not stainproof.

I've seen stainless rust like mild steel, I'm talking rusted away.... gone, in a very acidic steel pickling plant.

I have even seen rust spots on a mates stainless rifle barrel.

That would be "eaten", or digested, with a combination of strong acid (most likely Nitric acid) and heat generated in the pickling plant as opposed to "rust", which is typically oxidized.

However, so called "stainless rifle barrel" would be distinct from 316 grade stainless.

[Rippah]

That's why they call it stainless, not stainproof.

People don't want to hear that though. Then they have no excuse for being lazy and not cleaning their stainless rifle