What product form and what quantity?
Of course with the duplex grades you will use much less metal because of the higher strength.
How are you going to correct for that?
I can put them in order:
304L
2101
2202
316L
2507
But you left a few out, 2205 will cost just a little more than 316L but have much higher strength and corrosion resistance.
All of the 20-22 Cr lean duplex grades (<0.5 Mo) are very close in price.
Large OD pipe, do want it annealed or as welded?
Who in the US is going to make it? (there are only a couple of pipe mill left)
The last time that I ran numbers:
lean duplex grades were 1.05x 304L
2203 was about 1.25x
316L was 1.3x
People may be trying to charge more for the lean duplex because it isn't as common.
Remember if you were going to use 0.500" wall in 3xx you can use 0.375" in duplex, that will save you a ton of money.
Thank for your help Ed
I want welded pipes, I want just to take an order of magnitude of the prices before selecting the supplier as I did not choose him yet.
Run the design in 304L and then in 2101, compare the amount of metal required.
Even though 2101 is a little more per pound I think that you will find it significantly less expensive over all.
317L is only special order, so it needs to be a big job, about 2-2.5x the 304 price.
6%Mo is steep, at least 4x, maybe a little more. But these alloys are strong also so you can use less metal than with 3xx.
And these (like the duplex) really have to be made right, annealing, quenching, and cleaning are critical for corrosion resistance.
If you need that much corrosion resistance, if not then a lean duplex will win.
The lean duplexes are only a little more expensive per pound than 304, so factor in the strength and it is a deal.