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Title: Galling wear of cobalt-free hardfacing alloys. Final report

Abstract

Cobalt-base alloys have been used as hardfacing materials for nuclear power plant valves, turbines and pumps. In nuclear power plants cobalt is transported to reactor core region due to wear of valves and pumps; it is transmuted to Co{minus}60. Objective of this work was to find a cobalt-free hardfacing material that has better wear-resistance than the widely used cobalt-base alloy Stellite 6{sup TM} Six iron-base and four nickel-base alloys were compared to Stellite 6. The alloys were deposited on austenitic stainless steel by GTAW (Gas Tungsten Arc Welding), PTAW (Plasma Transferred Arc Welding), plasma spray fuse and laser processes. One alloy was in HIP (Hot Isostatic Pressed) condition. All alloys were tested for galling resistance in air at room temperature at applied stresses were 140, 275 and 415 MPa. Alloy microstructure and hardness values were post-test wear surfaces, were examined using a light and scanning electron microscopy, and microhardness measurements. Crack-free deposits can be manufactured from all of the alloys, and no problems were encountered during machining of the deposits. Self-mated galling resistance of Stellite 6 was comparable to galling resistance in earlier studies for this alloy. Self-mated iron-base Elmax, APM 2311, NOREM A, Nelsit, Everit 50 So alloys andmore » Ni-/Fe-base alloy combination showed significantly better galling behaviour than Stellite 6, especially Elmax and APM 2311 alloys. Nickel-base Deloro alloys showed galling resistance inferior to Stellite 6. No correlation was observed between the microstructural characteristics and galling resistance. Further, the galling resistance is not related to the hardness of the deposit.« less

Authors:
Publication Date:
Research Org.:
Electric Power Research Inst., Palo Alto, CA (United States); ABB Atom AB, Vaesteraas (Sweden)
Sponsoring Org.:
Electric Power Research Inst., Palo Alto, CA (United States)
OSTI Identifier:
10159620
Report Number(s):
EPRI-TR-103845
ON: UN94013647; TRN: 94:011164
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: May 1994
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 22 GENERAL STUDIES OF NUCLEAR REACTORS; 21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; HARD FACING; NUCLEAR POWER PLANTS; REACTOR COOLING SYSTEMS; MATERIALS; IRON BASE ALLOYS; WEAR RESISTANCE; NICKEL BASE ALLOYS; BWR TYPE REACTORS; PUMPS; VALVES; TURBINES; STELLITE 6; 360105; 220200; 210100; CORROSION AND EROSION; COMPONENTS AND ACCESSORIES; POWER REACTORS, NONBREEDING, LIGHT-WATER MODERATED, BOILING WATER COOLED

Citation Formats

Vikstroem, J. Galling wear of cobalt-free hardfacing alloys. Final report. United States: N. p., 1994. Web.
Vikstroem, J. Galling wear of cobalt-free hardfacing alloys. Final report. United States.
Vikstroem, J. Sun . "Galling wear of cobalt-free hardfacing alloys. Final report". United States.
@article{osti_10159620,
title = {Galling wear of cobalt-free hardfacing alloys. Final report},
author = {Vikstroem, J.},
abstractNote = {Cobalt-base alloys have been used as hardfacing materials for nuclear power plant valves, turbines and pumps. In nuclear power plants cobalt is transported to reactor core region due to wear of valves and pumps; it is transmuted to Co{minus}60. Objective of this work was to find a cobalt-free hardfacing material that has better wear-resistance than the widely used cobalt-base alloy Stellite 6{sup TM} Six iron-base and four nickel-base alloys were compared to Stellite 6. The alloys were deposited on austenitic stainless steel by GTAW (Gas Tungsten Arc Welding), PTAW (Plasma Transferred Arc Welding), plasma spray fuse and laser processes. One alloy was in HIP (Hot Isostatic Pressed) condition. All alloys were tested for galling resistance in air at room temperature at applied stresses were 140, 275 and 415 MPa. Alloy microstructure and hardness values were post-test wear surfaces, were examined using a light and scanning electron microscopy, and microhardness measurements. Crack-free deposits can be manufactured from all of the alloys, and no problems were encountered during machining of the deposits. Self-mated galling resistance of Stellite 6 was comparable to galling resistance in earlier studies for this alloy. Self-mated iron-base Elmax, APM 2311, NOREM A, Nelsit, Everit 50 So alloys and Ni-/Fe-base alloy combination showed significantly better galling behaviour than Stellite 6, especially Elmax and APM 2311 alloys. Nickel-base Deloro alloys showed galling resistance inferior to Stellite 6. No correlation was observed between the microstructural characteristics and galling resistance. Further, the galling resistance is not related to the hardness of the deposit.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1994},
month = {5}
}

Technical Report:
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