Calculating Yield Stress for Material at Elevated Temps

Yes, that is the best access.

Does ASME Sec II Part D have just static values or curves for different temps?

Most of the references I'm being given are just showing a single static value, which does me no good. I need either a curve or a formula to show the ystress value based on temps from room temp to 1400-1500F.

The reference I suggested has curves.

ASME II only has discrete values - but you can put them into Excel, plot them, put in a polynomial trend, and get the fit equation there.

Thanks.

Based on the original list I gave about the materials of interest, would the data for all or most of those be in ASME Sec II?

Next, other than paying $500 +/- how can I get the values only for the ystress at various temps for the materials? Seems steep given that all I need is a few ystress curves.

Can you confirm the exact Spec No. / Grade and/or UNS numbers for your materials?

If so, when I get some time I can pull it together for you.

Or how about a library, perhaps at a university/college nearby - they may have the ASME code.

Carbon Steel ASTM A 568

409 Stainless UNS S40920

304/304L Stainless UNS S30400/S30403

316L Stainless UNS S31603

309S Stainless UNS S30908

310 Stainless UNS S31008

Alloy 600/601 UNS N06600/N06601

Here you go:

http://ifile.it/eok82l7

You don't need to sign-up to download: just click on the "Request Download Ticket" in the top left corner, and then click on "Download" in the same spot.

Unfortunately, ASME did not list A568 steel, and the temperatures only list up to 1000 deg. F - so if you want higher you will need to look elsewhere.

That is fantastic. Is that from ASME Sec II Part D?

If anyone else has any other sources for going above 1000F I'd appreciate those as well.

I believe what I've found is exactly as someone had stated, each company has sort of done their own thing and no one has really compiled everything. You'd think that it would be useful for engineers to have a simple curve fit polynomial to calculate the yield strength at various temps. I'm guessing that everyone has their own formulae from their own curve interpretations. It's a shame there's not more collaborative efforts.

The MIL Handbook and the Metallic Material Properties guide (MMPDS-01) both have curves for Fty as a function of the room temp value, so you find the new value as a ratio to the room temp value. They show a curve that is the same for 301, 302, 304, 304L, 321, and 347 austenitic SS. They don't show any curves, that I can find, for 309S, 310, or 409 Stainless. Would those follow the same ratios from their room temp ystress values?

Just to clarify, I was looking for the values to 1500-1600F, knowing that some of these materials have other limitations preventing them from running in that range, such as Carbon steel, which would not be used over 1000F and likewise, 409 and 304 stainless would not be operated at those higher temps, but 1500-1600F was the highest I needed for any of the materials so that was the basis for my request.

Yes, those numbers are from ASME II-D;

I'll look in other sources I have and if I find out any more I will let you know.

The information you require can be found in "High-Temperature Property Data:Ferrous Alloys" published by ASM International.

Other good sources of materials data are matweb (www.matweb.com) which covers all sorts of materials (plastics, aluminium alloys, steels, superalloys etc) and is free; also the MIL Handbook - just type "mil handbook" into google and you can get a free copy of an old (but still v useful) version. This covers steels, aluminiums, titaniums etc but only metallic materials.

I have found an article entitled "Materials Properties Database for Selection of High-Temperature Alloys and Concepts of Alloy Design for SOFC Applications" on the web which has v good summaries of many elevated temperature properties of odd-ball materials. May not be directly useful but, like you, I have found little else in my searches.

good luck, DP

Hi again jchumley,

I understand your frustration - materials data is unfortunately one of those areas where the engineering world has been very poor at sharing its information in a good standardised way, probably because companies have had to pay considerable sums to gather "their" pieces of info, specific to their needs.

Similarly, over time, investigators have focussed on gathering data where it specifically impacts their, or their sponsors products, so the data appears to have vast holes when you stand back and want to review broad material choices.

The MIL Handbook that I referenced has graphs of yield strength at temperature for most of the alloys that you mention plus a huge amount more. What it doesn't have is them plotted together or overlaid in any way, so I'm afraid you have to do your own summarising/comparing. A new edition electronic version (that you have to pay for) may have capability of comparing alloys - I've never investigated it.

Hope that helps, DP

Spot on XMech - the MIL-HDBK-5H is the old version which is freely available to download and is v good (I also have a hard copy which does have some extra data/graphs).

I have not found the newest version

http://www.grantadesign.com/userarea/mil/mil5.htm

anywhere for free yet so haven't used it (being a good and frugal engineer always trying to keep the purse strings tight.....)

hope that gives enough info to answer the original post, DP

I'd saved the wonderful sites adresses suggested above.I just should add, at those temperatures, steel case for sample, is not steel any more, so even when some metals are used for high temps, and hard conditions,etc.The poster is asking too much even if he is ready to pay that sum may be those tables are not in existance and high temps designs are solved in a different way.-