Development of cobalt-free hard-facing alloys for nuclear applications: 1984 progress

Technical Report · Sun Sep 01 04:00:00 EDT 1985

OSTI ID:6496962

Ohriner, E W; Whelan, E P

Cobalt-free hardfacing alloys are needed to replace cobalt-base Alloy No. 6, used in nuclear valves, in order to reduce the radiation exposure of service personnel that is associated with cobalt 60. An analysis of the property requirements of nuclear hardfacing materials indicates that galling resistance is a critical property which is generally not associated with cobalt-free alloys. A series of cobalt-free alloys was selected for evaluation based on the available knowledge of wear and galling behavior of austenitic iron-base alloys. The experimental alloys were evaluated for galling resistance and for adhesive wear resistance in a crossed cylinder wear test in both air and deionized water environments at room ambient temperature. Tensile, impact, hardness and weldability properties of the alloys were also evaluated. An iron-base alloy has been identified with galling resistance properties equivalent to those of the Alloy No. 6 in tests in deionized water and in tests in air at loads up to 275 MPa (40 ksi). The effects of variations in Mn, Si, Ni and N contents on the wear, mechanical, and welding properties, and on the alloy microstructure have been determined. Galling tests have also been performed on many commercially produced low-cobalt and cobalt-free alloy hardfacings as well as laser remelted Alloy No. 156. 34 refs., 12 figs., 22 tabs.

• Research Organization: AMAX Materials Research Center, Ann Arbor, MI (USA)
• OSTI ID: 6496962
• Report Number(s): EPRI-NP-4237; ON: TI85920879
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
AUSTENITIC STEELS
BUILDUP
CONTROL EQUIPMENT
CONTROL ROD DRIVES
CORROSION RESISTANCE
ELEMENTS
EQUIPMENT
FLOW REGULATORS
HARD FACING
IRON ALLOYS
IRON BASE ALLOYS
MANGANESE
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
METALS
NICKEL
NITROGEN
NONMETALS
RADIATION PROTECTION
REACTOR COMPONENTS
SEMIMETALS
SILICON
STEELS
TRANSITION ELEMENTS
VALVES
WEAR
WELDABILITY