304LP vs 304L 4

[mighoser]

We had a supplier chose to use 304LP in lieu of 304L IAW ASTM A240.

1. Are there chemistry differences? Is Moly permitted in 304L?
2. Does 304LP meet ASTM A240? It isn't listed in the alloy table. The cert they send indicates it meets ASTM A240.

 

[XL83NL]

304LP? Whats the UNS number?

 

[mk3223]

The Supplier should provide you the detail property of 304LP, including the manufacture company, chemical property, service application, etc. So, you may compare them with A240-304L as you requested.

 

[metengr]

If you go to the Outokumpu web site the 304L under Prodec 304L is where the suffix P was added. The attached is a pdf on the material. It is self explanatory...

https://secure.outokumpu.com/steelfinder/GradeDataSheetv3PDF.aspx?OKGrade=4307&Category=Prodec

Is Moly permitted in 304L? For A/SA 240 Mo is not intentionally added nor specified for 304.
The Prodec 304L is UNS S30403, and is in A 240.

 

The Outokumpu information doesn't explain what makes this product special. Am I missing something obvious?

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[EdStainless]

It is free machining by virtue of inclusion shape control (not S, Pb, or Se).
And as such it still meets the 304/304L UNS and specs, and has the same corrosion resistance and weldability.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[moltenmetal]

Wow- that sounds magical- although "free machining" is no doubt a matter of degree.

 

[EdStainless]

2 or 3 times better than standard 304L is still pretty bad, but it is better than nothing.
One interesting bit of info, the newer lean duplex stainless alloys (2101, 2202, and so on) have very good machinability.
These alloys are much stronger than 304/316, and they have at least as good of corrosion resistance as 316.
I expect over the next 5 years to see them replace 300 alloys for all applications above -40C and below 600F unless very high elongations are required.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[XL83NL]

Interesting read Ed. Ive looked into this as well some years ago. I found the lean grades not be sufficiently interesting at the time being due to;-
- availability. In the EU, markets might have been different from US, but it wasn't that widespread available.
- product form. I was looking into the using this in pipe form mostly, for piping (say up to 4"), and standard fittings for building smaller (OD max 10") vessels with.
- size. Sinze we use a lot of smaller sizes, usually in combo with lower pressures, thickness savings were minimal and therefore material savings non-existent when reviewing e.g. 316 vs 2101.

You reckon these things may have changed?

 

[moltenmetal]

I don't think the availability of these grades is any better here in North America XL83NL

 

[dgallup]

How does Prodec 304L compare to Carpenter 304L Project 70+?

----------------------------------------

The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[EdStainless]

Availability may not be perfect yet, but it is getting much better.
You will not be able to find all product forms in one alloy, so you will likely end up having to use two or three different lean duplex grades. I have made HX tubing in three different ones, they all work fine.
If you are building a tall tank or silo the savings are huge, but you are correct that for many applications it is still a wash. In smaller sizes you often run up against minimum thickness long before you reach the lower limit for pressure containment.
When Ni goes back to $10/lb and Mo to $25/lb the switch will be permanent.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[moltenmetal]

When Ni goes back up to $10/lb, the Chinese will "fix" the problem again by making nickel pig iron. If moly ever goes back up to $25/lb though, you're right- things'll change. Then again, we've been waiting decades to see good availability of 2205 in small piping product forms and we still aren't there yet.

 

[mighoser]

Thank you everyone on the info on inclusion shape control and free machining. Is the improved machinability related to inclusion hardness? What is the connection/mechanism?

 

The inclusion shape and distribution assist with breaking up chips, an important aspect of machinability.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."