409 stainless steel piping 1

[bphil]

Hi,

I've tried to find 409 stainless steel piping for the last week. All I find is 409 tubing as per ASTM A268. But this kind of tubing is too thin for my needs. I need a 8" sch 80 409 stainless steel pipe.

I'm thinking about casting it now, does anybody knows where can I find such piping.

Phil

 

[mcguire]

It is rare to find 409 used in thickness over 0.060-0.070".
The mechanical properties fall off with increasing thickness. This is because it has to be cold reduced over 60% to get enough driving force for the full recrystallization which gives it a fine enough grain size not to be very lacking in toughness, hence not a favorite for much heavier in gage than exhaust pipe.

 

[DSR]

400 series alloys are subject to in-service embrittlement at high temperatures so be sure that your application is suitable and won't degrade the properties before you spend too much time looking for 409 pipe

 

[mcguire]

The 475C embrittlement ( alpha prime formation) only occurs in ferritic stainless steels with more then 15% chrome. 409, with its 11%, is immune.

 

[bphil]

Thank you guys,

so I conclude that I won't find it anywhere. What I'll probably do is cast it.

I really don't need strong mechanical properties for this application, it is just a corrosion allowance to protect from a mixture of air-HCl-chlorine gas at 500 C. It is not welded, it is supported by bracket and it act as a deflector.

thanx again

Phil

P.S. Hey, and the alloy can't have any nickel (less than 0.5%) ...

 

[mcguire]

Phil
Why don't you buy some sheet 409 and have it fabricated. Or get 410 which can be used in heavier gauges without these problems.

 

[bphil]

The reason why I don't fabricate it out of 409 plates is that it is very difficult to roll for 8" diameter and it is also very hard to find in thick (0.5&quot gage.

Thanx again

Phil

 

[mcguire]

Maybe you could use some 13Cr oil country tubulars. That sounds like a common geometry for them. You may be able to get a second quality or reject ( for downhole) relatively cheaply.