Evaluation of weldments in Type 21-6-9 stainless steel for Compact Ignition Tokamak structural applications: Phase 1
Primary design considerations for the Compact Ignition Tokamak toroidal field-coil cases are yield strength and toughness in the temperature range from 77 to 300 K. Type 21-6-9 stainless steel, also still known by its original Armco Steel Company trade name Nitronic 40, is the proposed alloy for this application. It has high yield strength and usually adequate base metal toughness, but weldments in thick sections have not been adequately characterized in terms of mechanical properties or hot-cracking propensity. In this study, weldability of the alloy in heavy sections and the mechanical properties of the resultant welds were investigated including tensile yield strength and Charpy V-notch toughness at 77 K and room temperature. Weldments were made in four different base metals using seven different filler metals. None of the weldments showed any indication of hot-cracking problems. All base metals, including weldment heat-affected zones, were found to have adequate strength and impact toughness at both test temperatures. Weld metals, on the other hand, except ERNiCr-3 and ENiCrFe-3 had impact toughnesses of less than 67 J at 77 K. Inconel 82 had an average weld metal impact toughness of over 135 J at 77 K, and although its strength at 77 K is less than that of type 21-6-9 base metal, at this point it is considered to be the first-choice filler metal. Phase 2 of this program will concentrate on composition refinement and process/procedure optimization for the generic ERNiCr-3 composition and will generate a design data base for base and weld metal, including tensile, fracture toughness, and crack growth rate data.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5147625
- Report Number(s):
- ORNL/TM-11739; ON: DE92000379; TRN: 91-028032
- Country of Publication:
- United States
- Language:
- English
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Thick-section weldments in 21-6-9 and 316LN stainless steel for fusion energy applications
Thick-section weldments in 21-6-9 and 316LN stainless steel for fusion energy applications
Related Subjects
36 MATERIALS SCIENCE
COMPACT IGNITION TOKAMAK
WELDED JOINTS
STAINLESS STEEL-21-6-9
WELDABILITY
CHARPY TEST
EVALUATION
MECHANICAL PROPERTIES
THERMONUCLEAR REACTOR MATERIALS
ALLOYS
AUSTENITIC STEELS
CHROMIUM ALLOYS
CLOSED PLASMA DEVICES
CORROSION RESISTANT ALLOYS
DESTRUCTIVE TESTING
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IMPACT TESTS
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MANGANESE ALLOYS
MATERIALS
MATERIALS TESTING
MECHANICAL TESTS
NICKEL ALLOYS
STEEL-CR21MN9NI6
STEELS
TESTING
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TOKAMAK DEVICES
TOKAMAK TYPE REACTORS
700209* - Fusion Power Plant Technology- Component Development & Materials Testing
360103 - Metals & Alloys- Mechanical Properties
360101 - Metals & Alloys- Preparation & Fabrication