MMR Advisor
Materials
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.
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.
