Rejection criteria for lamination/inclusions/banding in structural steel plate

[MMR Advisor]

I'm looking for a reference for standards-based acceptance/rejection criteria of microstructure of low alloy structural steel plate.
Background - during welding of structure, +45mm plate cracked at midline under thermal stress. Root mechanism determined to be mid-line lamination & non-metallic inclusions resulting from rolling process. Other lamination defects have been found, but the manufacturer is arguing that it meets defect size acceptance criteria per UT and PAUT examination(regardless of microstructure defects & previous failure).
Also noted significant ferrite/pearlite banding throughout multiple samples. ASTM E1268 gives guidance for measuring banding and quantifying anisotropy, but does not provide acceptance criteria. What's an unacceptable aspect ratio? Without getting into specifics, mechanical test results have some strange anomalies.

 

[Maui]

Acceptance criteria are communicated to the steel supplier through the material specification that is referenced on the purchase order. If no material specification is referenced, then you get what you get. I have written many of these types of specifications for a variety of companies who have encountered problems with incoming product.

Maui

 

[dik]

I have written many of these types of specifications for a variety of companies who have encountered problems with incoming product.

Can you post an example of a part to be included in a spec?

Dik

 

[metengr]

I would review ASTM A-20 and add supplementary requirements, as applicable.