A105 and A350 Raw Material

[marklobo]

Could someone please enlighten me how a mill could certify that a material in bar form complies with a forging specification? I've been trying to get a straight answer from our material suppliers, and am not satisfied with what I've been fed. Does ASTM A 961 have the answer?

If a manufacturer machines a part out of a piece of bar that was certified in compliance with A 105 or A 350 LF2, can they claim that the part is machined from a forging?

 

[Goahead]

A forging specification may impose requirements on raw material to be used for manufacturing forgings.
A part machined from a bar cannot be certified as being machined from a forging. A macrograph of a longitudinal section shows the difference. Forging process should be approved and possibly frozen.

http://www.welding-advisers.com/

 

[marklobo]

OK. Therefore a part machined from "forging stock" could only be allowable (per B16.34) if made from, per A 350 5.3.3, "rolled bar or seamless tubular materials provided that the axial length of the part is approximately parallel to the metal flow lines of the stock." In that case it would be considered a part made from bar rather than from a forging.

I find it interesting that B16.34 allows use of A 105 or A 350 without a reference to the qualifications in those specifications. How else would a manufacturer know that you could not machine a flange from that material? I feel more comfortable specifying complex, pressure-containing parts be made only from A 696 Gr C, than to risk high strains in a weak direction of the raw material.