tensile strenght @ elevated temperature for EN materials

[heymans]

Dear,

I am trying to make pipespecifications with both ASTM and EN materials according B31.3. I have still one remaining problem. For the EN materials I need tensile strenghts at elevated temperatures. In the EN codes these values are impossible to find. The approaching formule derived from B31.3 (calculating with yield strenght-ratio)is far too conservative. Has any got an idea where I can find reliable tensile strenghts or an approved approach

thanks

 

[InTheField]

If your in Canada, and I am assuming you are based on the B31.3 reference, you should refer to ASME Section II - it lists approved materials and strengths at temperatures (B31.3 refers to it but I can't remeber off hand what section it's in).

If your designing within a Canadian juristiction ensure that your calculations follow the code. to cross reference materials from look into the CASTI Black book.

 

[heymans]

InTheField,

My problem is not the materials listed in ASME II because these are all ASTM materials. My problem is calculating allowable stresses for EN/DIN materials according B31.3! B31.3 provides a formula with 4 'parameters': Rm20/3;Rmtemp/3;Ry20/1.5;Rytemp/1.5 Minimum of these values gives de allowable S. Problem is I can't find Rmtemp, tensile @ temperature,for EN materials. So I am looking for reliable EN-material tensile strenght or equations that approach these values.
B31.3 provides a formula: Rmtemp=(Rytemp/Ry20)*Rm20
Problem is this formula is far to conservative and for my appliciation thus unaccptable.

regards

 

[andyenergy]

What specifications do you need elevated propeties for? In EN10216 Part2 minimum proof stress values are given for elevated temperatures. It's a big table.

 

[heymans]

Andy,

I need tensile strenght at elevated temperatures.

 

[andyenergy]

Yes but specifically which grades of steel?

 

[heymans]

I would like them for all materials listed in EN10216-2
But P265GH would be a good start.

 

[andyenergy]

This isn't relevant to this thread but you might find it useful anyway:

http://www.vanleeuwenbuizen.nl/documents/1_50ug_Pipe_and_Tubes.pdf

This is relevant to your other thread:

http://www.astm.org/BOOKSTORE/PUBS/DS67B_SampleChapter.pdf

For P256GH, and wall thicknesses <= 60 mm, minimum proof stress values Rp0.2 are given in MPa (N/mm2). Temp first then value:

100 226
150 213
200 192
250 171
300 154
350 141
400 134
450 128.

There are 21 grades of steel listed.

 

[heymans]

Andy,

Thanks for to effort you put in trying to help me, but I think you misunderstood my question. The values you give me are Rp0.2 values (= yield strenght). I have full access to all EN-codes so also these values.
My problem are tensile strenghts (Rmtemp)! These strenght values seem impossible to find. [In fact it isnt so strange since EN is based on yield strenght and not (as is in ASME) on tensile.]

 

[andyenergy]

Errr. Yes seems I did. In which case it's going to be difficult to help you. Have you tried contacting steelmakers? The only thing I can suggest.

 

[TVP]

heymans,

What do you think about converting the EN grade to an ASTM equivalent grade, and then using the ASME allowable for that? I think the only way that you can obtain elevated temperature tensile strength data is from steel tube suppliers in the EU. I would start by contacting Dalmine/Tenaris.