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Title: Friction weld ductility and toughness as influenced by inclusion morphology

Abstract

Friction welding consistently provides high strength, freedom from fusion defects, and high productivity. However, friction welds in carbon steel exhibit impact toughness and bend ductility that are significantly lower than that of the base metal. The inclusion content and morphology were suspected to be major contributors to the reduction in weld ductility. For this reason, four electric furnace steels - three types of ASTM A516 Grade 70, and an ASTM A737 Grade B steel - were investigated. Friction welds were made by both the inertia and direct drive process variations and the welds evaluated. It was shown that friction welds of inclusion-controlled steels exhibited much improved toughness and bend ductility were demonstrated. Upper shelf impact energy was equivalent to or greater than that of the base metal in the short transverse direction. The transition temperature range for all four materials was shifted to higher temperatures for both types of friction welds. Under the conditions of this test, the direct drive friction welds showed a greater shift than the inertia friction welds. The ductility and toughness of welds in A737 Grade B steel were superior to welds in A516 Grade 70 steels, reflecting the superior properties of the base metal. Weldsmore » of the A737 material had usable Charpy V-notch impact toughness of 20 to 30 ft-lb (27 to 41 J) at temperatures as low as -40/sup 0/F (-40/sup 0/C). All the welds had an acicular structure. The differences in properties between the inertia and direct drive friction welds appear associated with microstructural variations. These variations resulted from the different heat inputs and cooling rates of the two process variations were demonstrated. The beneficial effects of inclusion control on toughness and ductility. In addition, it also indicates that additional improvements may be attainable through control of the as-welded microstructure by process manipulation.« less

Authors:
; ;
Publication Date:
Research Org.:
E.I. du Pont de Nemours and Co., Inc., Aiken, SC
OSTI Identifier:
6637700
DOE Contract Number:  
AC09-76SR00001
Resource Type:
Journal Article
Journal Name:
Weld. Res. (Miami); (United States)
Additional Journal Information:
Journal Name: Weld. Res. (Miami); (United States)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; FRICTION WELDING; EVALUATION; STEEL-ASTM-A516; DUCTILITY; FRACTURE PROPERTIES; WELDED JOINTS; WELDABILITY; ALLOYS; FABRICATION; IRON ALLOYS; IRON BASE ALLOYS; JOINING; JOINTS; MECHANICAL PROPERTIES; STEELS; TENSILE PROPERTIES; WELDING; 360101* - Metals & Alloys- Preparation & Fabrication

Citation Formats

Eberhard, B J, Schaaf, Jr, B W, and Wilson, A D. Friction weld ductility and toughness as influenced by inclusion morphology. United States: N. p., 1983. Web.
Eberhard, B J, Schaaf, Jr, B W, & Wilson, A D. Friction weld ductility and toughness as influenced by inclusion morphology. United States.
Eberhard, B J, Schaaf, Jr, B W, and Wilson, A D. Fri . "Friction weld ductility and toughness as influenced by inclusion morphology". United States.
@article{osti_6637700,
title = {Friction weld ductility and toughness as influenced by inclusion morphology},
author = {Eberhard, B J and Schaaf, Jr, B W and Wilson, A D},
abstractNote = {Friction welding consistently provides high strength, freedom from fusion defects, and high productivity. However, friction welds in carbon steel exhibit impact toughness and bend ductility that are significantly lower than that of the base metal. The inclusion content and morphology were suspected to be major contributors to the reduction in weld ductility. For this reason, four electric furnace steels - three types of ASTM A516 Grade 70, and an ASTM A737 Grade B steel - were investigated. Friction welds were made by both the inertia and direct drive process variations and the welds evaluated. It was shown that friction welds of inclusion-controlled steels exhibited much improved toughness and bend ductility were demonstrated. Upper shelf impact energy was equivalent to or greater than that of the base metal in the short transverse direction. The transition temperature range for all four materials was shifted to higher temperatures for both types of friction welds. Under the conditions of this test, the direct drive friction welds showed a greater shift than the inertia friction welds. The ductility and toughness of welds in A737 Grade B steel were superior to welds in A516 Grade 70 steels, reflecting the superior properties of the base metal. Welds of the A737 material had usable Charpy V-notch impact toughness of 20 to 30 ft-lb (27 to 41 J) at temperatures as low as -40/sup 0/F (-40/sup 0/C). All the welds had an acicular structure. The differences in properties between the inertia and direct drive friction welds appear associated with microstructural variations. These variations resulted from the different heat inputs and cooling rates of the two process variations were demonstrated. The beneficial effects of inclusion control on toughness and ductility. In addition, it also indicates that additional improvements may be attainable through control of the as-welded microstructure by process manipulation.},
doi = {},
journal = {Weld. Res. (Miami); (United States)},
number = ,
volume = ,
place = {United States},
year = {1983},
month = {7}
}