Inclusion analysis of A302 Grade B pressure vessel steel and the effect of the inclusions on toughness

Book · Wed Nov 01 04:00:00 EST 1995

OSTI ID:122617

Williams, J F ^[1]; Mager, T R ^[2]

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1. Westinghouse Science and Technology Center, Pittsburgh, PA (United States). Nuclear Services and Materials Testing
2. Westinghouse Energy Systems, Pittsburgh, PA (United States). Nuclear Technology Division

10CFR Part 50 Appendix G -- Fracture Toughness Requirements states that reactor pressure vessel materials must have Charpy upper-shelf energy of no less than 75 ft-lbs (102J) initially and must maintain upper-shelf energy throughout the life of the vessel of no less than 50 ft-lbs (68J), unless demonstrated in a manner approved by the Nuclear Regulatory Commission (NRC). The initial upper-shelf energy of reactor pressure vessel materials has been considered to be related to the inclusion content of the materials. Manganese sulfide (MnS) has long been identified in pressure vessel steels as the primary inclusion in pressure vessel steels. However, only recently has consideration been given to the relationship of the size and distribution of these inclusions on the fracture resistance of pressure vessel steels. For instance, how much of an influence does a low density of high density of MnS inclusions have on the Charpy upper shelf energy? This is the question which is reviewed in this paper. In this study, MnS inclusion ratings have been performed on four heats of A302 Grade B steel using scanning electron microscopy in combination with link Analytical FEATURESCAN and energy dispersive spectroscopy (EDS). The FEATURESCAN analysis yielded the size and distribution of the non-metallic inclusions, while the EDS determined the chemistries. The results of the microscope have been compared to existing Charpy data to show how the non-metallic inclusions influences the properties of the steels.

• OSTI ID: 122617
• Report Number(s): CONF-950740--; ISBN 0-7918-1335-5
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
EXPERIMENTAL DATA
FRACTURE PROPERTIES
INCLUSIONS
NUCLEAR POWER PLANTS
PRESSURE VESSELS
REACTOR MATERIALS
SCANNING ELECTRON MICROSCOPY
STEEL-ASTM-A302