Does 316 alloy rule over 304 ?

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Benchwrench

Benchwrench

Feeling the Heat
Sep 1, 2011
259
State of Confusion
I am curious if anyone has given this much thought, regarding the different alloys and high temp durations.

I am under the impression that sustained heat temps might warp a thinner 304 rigid liner if it was exposed to an overfire situation as in the case of Duraliner's 27 ga. 304 inner liner.

I am looking down the road for longevity and possibly a small chimney fire. I don't want to have to replace the liner if there ever became overfired.

My take on the matter is this;
If a rigid liner is of a thicker stock ie:24 ga. and/or a higher alloy ie:316, then it seems to reason that metalurgically it should be able to sustain higher and longer temps and may never need to be replaced even in the event of mild abuse , keeping into consideration how it is welded. Some may not be of a continuous weld whereas a spot weld product might get a wave between tacks. Thereby creating a breach for need of replacing.
 
316ti vs. 304 is a corrosion resistance issue, not a heat handling issue. And 304 is fine for the types of gasses in wood stove exhaust.
 
304 is what Pacific Energy uses in the Fireboxes other than a red oxidation works great and Lasts
 
Thicker is definitely better though.
 
If you have a hummer of a chimney fire in a factory built chimney and it is a hard packed type it is time to replace that pipe. The solid pack type pipe tends to harden its insulation with heat and due to the physics of expansion at high temps the pipe grows until it can no longer grow outward and it will buckle in. Any time you have a chimney fire it is time to do a thorough inspection of the system and replace as necessary. Then...don't have any more chimney fires!
 
BrotherBart said:
316ti vs. 304 is a corrosion resistance issue, not a heat handling issue. And 304 is fine for the types of gasses in wood stove exhaust.
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+1

If you read some of the literature on the 304 and 316 chimney offerings, 304 is suitable for wood, where 316 can handle wood or coal. When I bought my liner and class A chimney, being that I am only burning wood, I saw no need for the extra expense of 316.

Good luck,
Bill
 
leeave96 said:
BrotherBart said:
316ti vs. 304 is a corrosion resistance issue, not a heat handling issue. And 304 is fine for the types of gasses in wood stove exhaust.
Click to expand...

+1

If you read some of the literature on the 304 and 316 chimney offerings, 304 is suitable for wood, where 316 can handle wood or coal. When I bought my liner and class A chimney, being that I am only burning wood, I saw no need for the extra expense of 316.

Good luck,
Bill
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316 is better for higher pressure/heat applications , is more erosion, corrosion resistant and is a harder material than 304 stainless.

316 will withstand higher temps, but not to worry with temps like flu gases.


316 is a little more difficult to machine.
 
Hiram Maxim said:
...316 is better for higher pressure/heat applications , is more erosion, corrosion resistant and is a harder material than 304 stainless.

316 will withstand higher temps, but not to worry with temps like flu gases...
Click to expand...

It stood to reason that 316 would hold up over 304 in regard to elevated temps of a long duration.

I hope I'm not coming across as an extremist, I understand that flue temps should never get to the degree that would compromise liner integrity.

Duraliner claims to be .016 thickness which works out to be 27.5 gauge steel (304)

There are other rigid liners made of 24 ga. or .025 thickness that would require an insulated wrap. Whereas Duraliner already has a aluminized half inch (1/2") wrap, the others only offer a 1/4" aluminized wrap (from what I have gathered so far).

Thanks guys for helping me walk through the process of elimination choosing a liner,

Bench
 
In this situation, no. 316 for the ling and short contains more moly, molidneum. The nickle content is a hair different but nothing woryh discussing. Has nothing to due with heat or longevity, unless your talking about corrosion. Which is as stated wood vs coal. Some liners advertise titanium in the mix....let me say any tiny amount present isnt helping anything in a chimney liner.
 
Stump_Branch said:
Some liners advertise titanium in the mix....let me say any tiny amount present isnt helping anything in a chimney liner.
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That's for sure! Titanium and high heat don't get along so well like 300 series stainless....
 
Benchwrench said:
Hiram Maxim said:
...316 is better for higher pressure/heat applications , is more erosion, corrosion resistant and is a harder material than 304 stainless.

316 will withstand higher temps, but not to worry with temps like flu gases...
Click to expand...

It stood to reason that 316 would hold up over 304 in regard to elevated temps of a long duration.



Bench
Click to expand...

Without a doubt.
 
Which is it Hiram? 316ti is titanium stabilized alloy. So are you saying it handles heat better or not. I say it handles corrosive gasses better but no better for heat. And we are talking broil foil thickness here. Not machinable size sticks.
 
Pure titanium naturally oxidizes under high heat. We use it as a capturing device, or filter as you will, at work. It's heated to a temp where it captures and retains oxygen molecules via oxidation. It's properties may change when alloyed with the 316SS but I'm not familiar with that particular blend.

316 and 304 are rated to handle the same heat ranges. Both begin to oxidize at 1800 deg F. 316 is designed to be more resistant to chemical corrosion. (Coal exhaust contains sulphur which can combine with moisture in the pipe to create sulphiric acid.

Wonder if anybody makes Inconel liners/pipe? That would be some serious $$$$.
 
Titanium alloys are used a lot in very high temperature applications where strength and light weight are required. Jet engines have lots of titanium alloy.
Did you know titanium is very abundant... like the ninth most abundant element on earth? Problem is it's never in pure form... always bonded to other elements and in oxide form and has to be processed.
 
mhrischuk said:
Titanium alloys are used a lot in very high temperature applications where strength and light weight are required. Jet engines have lots of titanium alloy.
Did you know titanium is very abundant... like the ninth most abundant element on earth? Problem is it's never in pure form... always bonded to other elements and in oxide form and has to be processed.
Click to expand...

Titanium oxide is the "white" in paint.
 
MasterMech said:
Pure titanium naturally oxidizes under high heat. We use it as a capturing device, or filter as you will, at work. It's heated to a temp where it captures and retains oxygen molecules via oxidation. It's properties may change when alloyed with the 316SS but I'm not familiar with that particular blend.

316 and 304 are rated to handle the same heat ranges. Both begin to oxidize at 1800 deg F. 316 is designed to be more resistant to chemical corrosion. (Coal exhaust contains sulphur which can combine with moisture in the pipe to create sulphiric acid.

Wonder if anybody makes Inconel liners/pipe? That would be some serious $$$$.
Click to expand...

Much agreed. For HEAT no difference, corrosion 316 is better.
 
mhrischuk said:
Titanium alloys are used a lot in very high temperature applications where strength and light weight are required. Jet engines have lots of titanium alloy.
Did you know titanium is very abundant... like the ninth most abundant element on earth? Problem is it's never in pure form... always bonded to other elements and in oxide form and has to be processed.
Click to expand...

You have any idea how much Titanium you eat? Check it out. Titanium Dioxide is in just about everything from Shampoo to TV Dinners, lol.
 
BrotherBart said:
Which is it Hiram? 316ti is titanium stabilized alloy. So are you saying it handles heat better or not. I say it handles corrosive gasses better but no better for heat. And we are talking broil foil thickness here. Not machinable size sticks.
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BB, Sorry if I'm confusing...I was saying that 316 is better for high heat over Titanium. And I was talking overall material not just broil foil.

In my industry (firearms and Firearm Silencers) Titanium is used for lower temperature application and 316 and inconnel are used for high temp applications.

I'm not familiar with 316Ti

Without getting to technical or in a huge material debate I agree that handles 316 corrosive gasses better, but I will stand by my statement that I believe from what I have personally witnessed that 316 will hold up to heat better than 304. Just my opinion :cheese:

Below is a picture of a 5.56 suppressor made of 316 ss and internal baffle stack made of inconel 718

You cant abuse Titanium like that.....

Apples and Oranges right? ;-P
 

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There must be something to alloy and heat rating but just isn't a factor for our purpose of heating a home or shop.
I heard somwhere 321 is used on aircraft afterburner nozzles.
Thanks guys for chiming in on the topic, I guess when it comes to wood burning, 304 will be plenty adequate since extreme temps aren't going to be into play.
 
Long and short - 304 is fine. The sulfurs in coal....well, 316 starts to make sense, except 304 is usually fine if you clean it!

To make it longer, a number of insulated chimney makers use 400 series (430), at least on the outside. Sure, that's not taking the heat, but it does have to take corrosion.

This stuff IS a real science - and always some kind of compromise between machinability, WHICH stuff corrodes it...and at which temperatures and finishes, etc. etc. etc.....

That's why I love engineers. It's also why I like woodstoves....they don't fall from 40,000 feet if we used a slightly different grade!
 
Yeah but I want Hiram to make me a really nice silencer for my Ruger Super Blackhawk out of whatever he feels is appropriate. :cheese:
 
I don't think silencer and Super Blackhawk can be in the same sentence.
 
BrotherBart said:
Yeah but I want Hiram to make me a really nice silencer for my Ruger Super Blackhawk out of whatever he feels is appropriate. :cheese:
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BB,

If You want to pay, we can play! ;-P

However the gap between the cylinder and barrel will make it far from hearing safe.(I'm pretty sure your aware of that)

But there are suppressed revolvers.......
 
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