A395 Sm value

[HookedOnHalo]

I've been through Section II, Part D, Table 2A several times and can't find Sm list for A395. Other cast material is listed in this section but not A395. Have I missed it or am I missing something about this material and how Sm is applied to it?

 

[unclesyd]

I have it listed as Nodular Iron (3C-3Si). It is listed under code case 1939.

UNS number 32800

UTS 60,000

YS 40,000

 

[HookedOnHalo]

Thanks for the help but I was able to find the UTS and YS from a couple sources. I was looking for the Design Stress Intensity values that is listed in Table 2a for Part D of Section II of the code. There are several casting materials listed in Table 2a but for some reason A395 is not listed (or I can't find it!)

 

[unclesyd]

I don't have access to the Code Case posted above so I can't say whether its been incorporated in the Code or dropped. Hopefully someone will look it up and post.

 

[HookedOnHalo]

thanks again for the reply. Hopefully someone can help.

 

[doct9960]

Hooked,

SA-395 is not listed in Table 2A.

What particular ASME code are you intending to use SA-395?

 

[HookedOnHalo]

The material is being used for casting of a recip compressor cylinder. We are doing a 3D fea of the cylinder to assess stress. Initial thoughts were to use Sm value to evaluate the results. Perhaps will use Modified Goodman fatigue approach instead. There are not specific code requirement for the evaluation.

 

[metengr]

For S_m you can approximate a value that is 50% of the minimum specified YS.

 

[HookedOnHalo]

metengr,

Thanks for the info.

Is there any reference you can give for this or just based on your experience?

 

[metengr]

HookedOnHalo;
My statement above regarding the value of S_m is based on the maximum stress theory used by ASME B&PV code.
Yielding can be determined by two current approaches;
the maximum shear stress (Tresca) or the maximum distortion energy (vonMises).

The simplest is the maximum shear stress theory where yielding occurs when the maximum shear stress value reaches 1/2 the tensile yield stregnth.

Ref;
Pressure Vessels and Piping: Design and Analysis A Decade of Progress

Editors;
G Bohm
L Hsu
R Cloud
D Pai
R Reedy

ASME Publication