4130 Question

[anne_pe]

4130 steel per AMS-S-6758:

Condition D2 => D=normalized, 2=pickled or blast cleaned

Condition D4 => D=normalized, 4=cold finished (drawn)

Is condition D4 a stronger material because its cold worked? Or are the mechanical properties the same and the surface condition of the "4" is as-drawn whereas the "2" is blast cleaned?

I have a drawing that specifies Condition D2 and I only can find Condition D4 available. Are they mechanically equivalent? Is there any reference material that will help me?

Thank you in advance for your reply.

 

[TugboatEng]

You can take D4 and have it blast cleaned or pickled to meet D2.

 

[EdStainless]

Does the higher strength D4 meet the elongation and impact requirements of D2?

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P.E. Metallurgy, consulting work welcomed

 

[anne_pe]

EdStainless, Is D4 stronger than D2? I can't find any references that tell me. It's not in the material spec nor is it in the MMPDS. Do you have any references on this subject that would clarify the physical properties of these two conditions? Thanks.

 

[EdStainless]

I don't have a copy of 6758 on hand, are these just surface finish descriptions?
The mechanical properties must be listed there if the material is in the MMPDS.
IF there is just one set of properties then this refers only to surface condition.

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P.E. Metallurgy, consulting work welcomed

 

[SwinnyGG]

The second number in the code is surface treatment only.

As long as the D in Dx is a D, you're getting normalized bar and the same bulk properties.

 

[WKTaylor]

Ed...

AMS-S-6758A ~= MIL-S-6758B

https://quicksearch.dla.mil/qsSearch.aspx

search for MIL-S-6758B

Regards, Wil Taylor
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