Information about CREEP Rate

[ammsp]

Hi!

I need some information. I`m studying a project which ASME Section II Part D is my road map. Analyzing Table 1-100 i get doubet about the CREEP Rate. Where can i find/calculate him??? my material is AISI 304H at temperature 1375ºF. Then which one of them i consider as allowable stress???

Much obliged

 

[metengr]

Your post is confusing, what is Table 1-100i in ASME Section II Part D? There is a Table 1A which contains allowable stress values, and mandatory appendices which provide guidance on how to establish allowable stress values.

 

[ammsp]

OK,

It´s Table 1-100 (CRITERIA FOR ESTABLISHING ALLOWABLE STRESS VALUES FOR TABLES 1A AND 1B) for welded pipe. My doubt is where to find the CREEP Rate for my material. Is there any table or code whith creep rate??

 

[metengr]

Thanks for the follow-up. Ok, you are referring to Mandatory Appendix 1, Table 1-100 In Part D. The allowable stress values for determination of time dependent allowable stress values, like creep deformation or stress rupture, are provided at the time a request is made for use of material. In other words, the data submittal is provided to the code committee members and is not part of an ASME database. So, creep rate data is submitted by the organization interested in having the material listed by ASME B&PV Code.

 

[ammsp]

So resuming, I need to send to the code committee members my material data for them send me the creep rate data??

isn´t there another way out? to find data for my material that gives me an average stress to produce a determined creep rate??

 

[SnTMan]

ammsp, "my material is AISI 304H at temperature 1375ºF. Then which one of them i consider as allowable stress???" & "for welded pipe"

It appears to me your allowable is 2250 psi per Sec II, Part D, Table 1A, pg 89, line 42 (higher allowable Note G5).

Regards,

Mike

 

[SnTMan]

Forgot to add, this would be for Sec VIII, Div 1 work.

 

[metengr]

Creep rate and allowable stress are not one in the same. If all you need is allowable stress, the above provided by SnTMan is correct. If you need a specific creep deformation rate per your original post as a function of stress, you will not find this from Table 1A.

 

[ammsp]

OK this is helping,

But i have a doubt, Mister SnTMan the value of the allowable stress from the table do consider creep influence??

Because checking my work, I need to define a allowable stress with influence of the creep.

I´m using ASME Section VIII Divison 2

 

[SnTMan]

ammsp, per Sec II, Part D, Table 5A, pg 413, line 2 the allowable is also 2250 psi for Div 2 work (thanks for specifying). It is based on time dependent properties, as per note T9. Established per Mandatory Appendix 10.

I might observe you do not appear to be familiar with the Code.

Regards,

Mike