The Home Machinist!

Sftyvlv wrote: ↑Fri May 25, 2018 9:05 pm Anybody ever use 1 1/4, 2 1/4 chrome (asme A 335) pipe and or plate equivalent for boiler fab.
Has great high pressure/high temp qualities and probably some anti corrosive properties as well.

*ASTM SA 335

How does monel or inconel compare to the duplex ss?

No comment What do I know anyway.

What stainless steel alloy would be best for piston rods?
We're rebuilding a sorely abused Locomobile motor for the WAAAMuseum in Hood River, OR.
~R

As already been mentioned ss is no good for boilers because of the metallurgical problems that accompany it.
Having said that. It is used in in UNFIRED pressure vessels and process piping. Provided it doesnt reach the temp at which carbide precipitation occurs its all good.
Fireside of heating surfaces is where the problem could occur. Same with flues. Superheater units are out of the question.
The only way ss might be useful is on outer shell and plate surfaces not exposed to the direct heat of combustion.

It’s a lot easier and more effective to set up a good water treatment program at each club. Especially as many use one water source for the whole track. Depending on the initial water conditions we could set up softeners and test the water regularly. We could even install off the shelf filters to remove minerals since the quantities of water are low. Then the oxygen scavengers and such can be added as needed. This is exactly what is used for full size locomotives with old carbon steel boilers and it works great!

What is the source for all your advice? Do you have an engineering degree? I'm not trying to be critical of your post just asking the question

Trainman4602 wrote: ↑Sat May 26, 2018 12:30 pm What is the source for all your advice? Do you have an engineering degree? I'm not trying to be critical of your post just asking the question

Who are you addressing?

YOU

NP317 wrote: ↑Sat May 26, 2018 9:43 am What stainless steel alloy would be best for piston rods?
We're rebuilding a sorely abused Locomobile motor for the WAAAMuseum in Hood River, OR.
~R

Pretty much any stainless alloy will serve, but the 300 series tends to be easy to gall, so I'd avoid them unless I had no alternative.
Of all the stainless alloys, 416 is the easiest to machine, and yields a great finish. It is also capable of being heat treated, unlike the 300 series of alloys. If I had the option, I'd likely choose that alloy, and heat treat the rod, which enhances its corrosion resistance and would extend its useful life (less wear).

You could also consider the use of 17-4 PH, although for what ever reason, the maker instructs that the material should not be put in service in the solution annealed condition, but should be heat treated. It can be machined in the H1000 condition, or even greater (H1250), but you'd likely enjoy success even in the H900 condition. It's tough, but it will machine.

Bottom line? I'd still shoot for 416.

H

Berkman wrote: ↑Sat May 26, 2018 8:08 am How does monel or inconel compare to the duplex ss?

Neither of them would be an acceptable option, due to their cost. The average guy couldn't afford them. They make copper look like a bargain.

H

My question was more a hypothetical, just curious how they would work. Not going to suggest going out and buying it. the average guy can't afford a 7-8k boiler for a mikado either...