Accelerated steam plus hydrogen tests for Alloy 600 wrought and welded specimens
- Westinghouse Bettis, West Mifflin, PA (United States)
- Westinghouse Science and Technology Center, Pittsburgh, PA (United States)
A chemical cracking test has been used to quickly obtain intergranular stress corrosion cracking (SCC) as it occurs in Alloy 600 wrought metal and EN82 weld metal in deaerated high temperature water environments. The test, referred to hereafter as the doped steam test, involves exposing the specimen surface of interest to 3000 psig (20.7 MPa), 750 F (400 C) superheated stagnant steam raised from water that contains 100 ppm each of chloride, fluoride, sulfate, and nitrate sodium salts and to 10 psia (69 kPa) hydrogen partial pressure. Alloy 600 and EN82 bent beam specimens loaded to various known stress levels were exposed to this doped steam environment for periods of one to eight weeks. Threshold behaviors were determined from this test series. For specimens loaded above the threshold stress, SCC occurred in less than one week. Welded specimens with partial penetration EN82 welds were also subjected to the doped steam environment in the built-in crevice associated with partial penetration welds. During this test, cracking occurred in both the weld and wrought materials. The weld cracks initiated at the root and grew through the entire thickness of the weld throat in two weeks. Metallographic sections in the crack region and fractographs of the weld crack surface confirmed the presence of the multiple branched intergranular cracking expected in SCC. The results clearly indicate that the superheated stagnant steam with hydrogen and these four dopants provides a useful environment to assess the tensile stress condition of Alloy 600 wrought metal and EN82 weld metal specimens.
- DOE Contract Number:
- AC11-93PN38195
- OSTI ID:
- 203793
- Report Number(s):
- CONF-950816-; ISBN 1-877914-95-9; TRN: 96:009759
- Resource Relation:
- Conference: 7. international symposium on environmental degradation of materials in nuclear power plants: water reactors, Breckenridge, CO (United States), 6-10 Aug 1995; Other Information: PBD: 1995; Related Information: Is Part Of Seventh international symposium on environmental degradation of materials in nuclear power systems -- Water reactors: Proceedings and symposium discussions. Volume 1; Airey, G.; Andresen, P.; Brown, J. [eds.] [and others]; PB: 664 p.
- Country of Publication:
- United States
- Language:
- English
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