CAESAR II - EN13480 Material Allowable

Posted by: MIOTTI SIMONE

CAESAR II - EN13480 Material Allowable - 04/23/10 08:20 AM



In Material Database of CAESAR II 5.1 about material P235GH (1.0345), the value of allowable doesen't match with rules of EN 13480-3 chapter 5.2.1.1. (i.e. Rp0,2t at room temperature of this material is 235000 KPa by EN10028, allowable stress should be Rp0,2t/1.5, and for all range of temperature should change).

Please can you explain me how are obtained allowable for EN material with EN13480 code?
Thanks
Best Regards
Posted by: Ray_Delaforce

Re: CAESAR II - EN13480 Material Allowable - 04/23/10 03:03 PM

Hello Miotti

EN 13480-3 does not directly give the 0,2% proof stress of P235GH material. As you point out, we have to go to a specification such as EN 10028. From my copy of that specification, at 20C (room temperature) the value of Rp0,2t is 235 MPa. The value of Rm is 360 MPa. Up to a temperature of 50C the f = min(Rm/2,4; Rp0,2(20C)/1,5) Thus, up to a temperature of 50C, the design stress is min(360/2,4; 235/1,5) = 150 MPa. Once the temperature goes over 50C, the stresses drop. For example, at 100C, Rp0,2%t is 198 MPa, thus f = min(360/2,4; 198/1,5) = 132 MPa. Just remember, up 50C, the design stress is based up the yield at 20C (or room temperature).
Posted by: MIOTTI SIMONE

Re: CAESAR II - EN13480 Material Allowable - 04/26/10 03:32 AM

Hello Delaforce,
thanks for answered at my question.
In my version of CII 5.10.03(Build 090206) allowable of 1.0345S-16 from -40°C to 170,5°C is costant =120MPa, at 200°C allowable is 113,3MPa. In your example at 150°C, Rp0,2% is 198MPa thus f = min(360/2,4; 198/1,5) = 132 MPa, ok I agree, in CII material database at 150°C i found allowable 120MPa because in EN13480-3 chapter 12.1.3.2 fc=min(Rm/3;froom) & fh=min(fc;ft;fcr) thus 360/3=120 < 132, it matches with CII material database.

At 200°C Rp0,2% is 182MPa and ft= 182/1,5 = 121,3MPa thus fmin=120MPa, why in CII is 113,3MPa? Creep start at 380°C thus fcr is not considered in equation, is it right?.

At 400°C (creep range) value of Creep Rupture strenght is 191MPa for 10000h, 132MPa for 100000h and 115MPa for 200000h. fcr = SRTt/SFcr=132/1,5= 88MPa or 115/1,25= 92MPa [SFcr by table 5.3.2-1 EN13480-3]. In CII value of allowable is 74,67MPa, i don't understand how is calculated, please can you explain me how are obtained?.

Thanks
Best Regards
Posted by: Ray_Delaforce

Re: CAESAR II - EN13480 Material Allowable - 04/26/10 12:16 PM

Hello Simone, I aplogise for using your last name. I couldn't figure out which was your first, and which was your last.

From -40C to 50C generally a non austenitic steel has the same design stress. After 50C the design stress is govenered by the formula: f = min(Rm/2,4; Rp0,2%t/1,5). The streses may begin to drop at different temperatures for different materials. Using your exmaple, we consider a P235GH material. If we take the value from EN 20216, Rp0,02t at 200C it is 170 MPa. Thus, the final stress value would be 170/1,5 = 113,333 MPa. If you take the 0,2% proof stress from EN10028, you will get a different value from if you take it from EN 20216, which is a piping material.

We used the piping material specification for the production of the Caesar material database.

In America we are not so familiar with the EN materials that are used in Europe. We are always open to correction if we err. Also, we do not have ready access to the European code committees. I have tried to raise a question with them but I never got a reply.
Posted by: MIOTTI SIMONE

Re: CAESAR II - EN13480 Material Allowable - 04/29/10 02:45 AM

Hello Ray,
there is no reason for apologising, no problem!
First of all thanks for answered at all my questions.

I aplogise with you for my mistake, for P235GH code is EN10216 (Seamless tube product) while EN10028 is used for flate product... Sorry.
CII material database has material number 1.0345 (P235GH) but EN13480-2 assigns this material number at flat product (EN10028) or welded tube (EN 10217-5) made in P235GH, while for seamless tube product (EN10216-2) don't give a number material, for this reason i am confused and i wrong.
Another simple question, 1.0345S-16/1.0345W-16: S=seamless, W=welded &
16=maximum thickness?
This is my first job using EN code, i always used ASME code and for this reason i am in trouble.

Thanks
Best regards
Posted by: Richard Ay

Re: CAESAR II - EN13480 Material Allowable - 04/29/10 12:49 PM

Yes, the "-16" means 16mm maximum thickness.