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Identifying type 304 stainless steel flange defects using scanning Auger microscopy (SAM)
Author(s) -
Eberle W. J.,
Clough S. P.
Publication year - 1990
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.740150213
Subject(s) - materials science , microstructure , flange , machinability , auger , metallurgy , austenitic stainless steel , austenite , ferrite (magnet) , optical microscope , composite material , scanning electron microscope , corrosion , machining , mechanical engineering , engineering
An unusual number of large stringer defects were found in cross‐forged type 304 austenitic stainless steel ultrahigh vacuum (UHV) flanges. These defects are cosmetically displeasing, they can affect the material's machinability and they can also affect the vacuum integrity of a UHV system. In this study, scanning Auger microscopy was used to identify accurately the defects as ferritic inclusions. This information was used to justify a change in forging and heat‐treating procedures, resulting in the reduction of large ferrite segregants and creating a more homogeneous microstructure. Subsequently, the rejection rate was reduced more than 50‐fold.