ASME II Part D Definition of "Nominal Chemical Composition"

[Ganfoss2]

Does someone know the criteria to "group" the ASME Materials inside one of the family stated inside the ASME Section II Part D?

Example of AMSE II-D Groups for the Nominal Compoitions:

1 Cr - 1/2 Mo
1 1/4 Cr - 1/2 Mo - Si
2 1/4 Cr - 1Mo
2 1/4 Cr - 1Mo - V
Mn - 1/2 Mo
Mn - 1/2 Mo - 3/4 Ni
16Cr - 12Ni - 2Mo
18Cr - 2Mo
27Ni - 22Cr - 7Mo - Mn - Cu - N

Many thanks in advance,

ANN

 

[SnTMan]

Sec II, Part A

 

[Ganfoss2]

Thanks to your reply, but I have ill conditioned my question, sorry!

Starting from the list of elements that constitute an alloy (generally expressed in a range format, as stated in ASME II/A or II/B), there is a "criteria" by which it is possible to group a specific alloy under one of the possibly "family" listed in ASME II Part D or create a new "family" of alloy?

Example: P355NH of EN 10028-2
It "significant"/"most in content" elements are here below listed:

C = 0.18 MAX
Mn = 1.10 to 1.70
Si = 0.5 MAX
Ni = 0.5 MAX
Cr = 0.3 MAX
Cu = 0.3 MAX
V = 0.1 MAX

plus other other elements non high in percentage ("minor").

For me this material may be "Group" as follow:

"Carbon Steel" Alloy Steel Group
(Very General Family)

OR

"C-Mn-Si-Ni" Alloy Steel Group
(a simply list of most significant elements in the alloy)

OR

"C - 1 1/2 Mn" Alloy Steel Group
(Mn is a very important alloy element under the
strength capabilities, more than Ni, Cr, Cu and V
Si acts as a de-oxidiser and it is used as Grain
Refinement)

FOR REFERENCE:

The classical SA-516 Grade 70 has been classified as "Carbon Steel" (Very Wide Family) and it has the following composition:

C = 0.31 MAX (depend from range of THK.s)
Mn = 0.80 to 1.30 (partial overlap)
Si = 0.15 to 0.40 (partial overlap)

(NOTE: Other elements not retrieved.)

It is very strange that in the ASME IID there is NO reference to the Criteria used to group the materials under their Nominal Chemical Composition.

If somebody has an idea ... just for my knowledge!

many thanks in advance,

ANN

 

[SnTMan]

Ganfoss2, up until a few years back (don't remember how few) Sec II Part D was more descpritive of the materials classifications, listing SA-516-70 as C-Mn-Si for example, where now, as you note, it is classified as just CS.

I thought the more detailed descriptions were useful, don't know why they were changed.

Sorry, I don't know how to answer your question.

Regards,

Mike

 

[ulyssess]

I do not understand your problem. For most tables, like Y-1 or 5A the material grouping is perhaps helpful for sorting the table. The indicated values are related to a specification number like SA516 and eventually a grade/type.
For materials not listed like P355NH, ASME II Part D can not be applied.

 

[Ganfoss2]

Thanks to alls for your reply.

Material orting with "Groups" is a very easy criteria to find data in short time. It is also useful when I have to perform MIX DESIGN (ASME Code with EN Materials or EN 13445 Code with ASME Materials): this key is very useful when I have to deal with a Pressure Vessel Design that take in account the value of the Elastic Modulus (E) + Thermal Expansion Factor (Alpha) vs. temperature or when I have to perform a Thermal Transient or Static Analisys ( I have to know the tabular value vs. temperature of the Thermal Conductace (k) + Thermal Capacity (c) ).

i.e.: Fixed Tubesheet Design or Stress Discontinuity Analisys or FEA.

It is very difficult to get the value of E, Alpha, c and k vs. Temperature directly from the Steel Makers or by the avaiable Technical Literature so sometime happpens that I have to find "equivalences" between materials and this key let me more speedy and secure to estabish an "equivalence" material (ie. P355NH and SA-516/70 or to find E and Alpha Data for the 15NiCuMoNb5-6-4 material).

If somebody inside ASME Technical Committee has decide to define groups for the most common used materials under the point of view on their material's Termo-Mechanical Properties ... perhaps my error when I define an "Equivalence" may be ... neglectable!

This is the origin of my question