Microstructural Evolution of HSLA ISO 3183 X80M (API 5L X80) Friction Stir Welded Joints
Microstructural Evolution of HSLA ISO 3183 X80M (API 5L X80) Friction Stir Welded Joints
Tahiana F. C. Hermenegildo(Universidade Federal de Pernambuco); Tiago F. A. Santos(Universidade Federal de Pernambuco); Edwar A. Torres(Universidad de Antioquia); Conrado R. M. Afonso(Universidade Federal de São Carlos); Antonio J. Ramirez(Ohio State University)
24권 5호, 1120~1132쪽
초록
Evaluation was made of friction stir welded joints, identifying conditions that resulted in satisfactory welded joints free fromdefects and with microstructural characteristics that provided good mechanical properties. Microstructural characterizationand cooling curve analysis of the joints with lower and higher heat inputs evidenced deformation below and above the nonrecrystallizationtemperature (T nr ) and dynamic recrystallization during microstructural evolution. Microscopy analysesshowed acicular ferrite, bainitic ferrite, and coalesced bainite microstructures in the stir zone of the cold weld (lower heatinput), while the stir zone of the hot weld (higher heat input) contained bainitic ferrite, acicular ferrite, coalesced bainite,martensite, and dispersed carbides. Granular bainite and dispersed carbides were observed in all the heat aff ected zones. Analysis of the microstructural transformations, together with the thermal history of the joints, showed that the variable thathad the greatest infl uence on the morphology of the bainite (granular bainite/bainitic ferrite) was the deformation temperature.
Abstract
Evaluation was made of friction stir welded joints, identifying conditions that resulted in satisfactory welded joints free fromdefects and with microstructural characteristics that provided good mechanical properties. Microstructural characterizationand cooling curve analysis of the joints with lower and higher heat inputs evidenced deformation below and above the nonrecrystallizationtemperature (T nr ) and dynamic recrystallization during microstructural evolution. Microscopy analysesshowed acicular ferrite, bainitic ferrite, and coalesced bainite microstructures in the stir zone of the cold weld (lower heatinput), while the stir zone of the hot weld (higher heat input) contained bainitic ferrite, acicular ferrite, coalesced bainite,martensite, and dispersed carbides. Granular bainite and dispersed carbides were observed in all the heat aff ected zones. Analysis of the microstructural transformations, together with the thermal history of the joints, showed that the variable thathad the greatest infl uence on the morphology of the bainite (granular bainite/bainitic ferrite) was the deformation temperature.
- 발행기관:
- 대한금속·재료학회
- 분류:
- 재료공학