151 0

Application of Nonlinear Ultrasonic Effect for Evaluation of Characteristics of the Heat Affected Zone in Welded Ferrite-Bainite High Strength Steel

Title
Application of Nonlinear Ultrasonic Effect for Evaluation of Characteristics of the Heat Affected Zone in Welded Ferrite-Bainite High Strength Steel
Author
Young-Jin Lee
Alternative Author(s)
이영진
Advisor(s)
장경영
Issue Date
2019-02
Publisher
한양대학교
Degree
Master
Abstract
The high-strength steel is normally subjected to a welding process when used in a structure. And a heat-affected zone (HAZ) with completely different microstructures and mechanical properties from the base metal is created. The toughness of the HAZ is reduced compared to the base metal, which affects the stability of the structure. Therefore, it is need to control microstructure of HAZ and evaluate it. This study verified that the nonlinear ultrasonic technique could effectively detect the microstructural changes in the HAZ. For this purpose, 590 MPa grade ferrite–bainite high-strength steel specimens were prepared with different grain sizes by varying the heat exposure time in an electric furnace. Then, a ultrasonic velocity and a relative ultrasonic nonlinear parameter were measured in four types of specimens. The experimental results showed that the relative ultrasonic nonlinear parameter and hardness tended to decrease as the grain size increase.
URI
https://repository.hanyang.ac.kr/handle/20.500.11754/99470http://hanyang.dcollection.net/common/orgView/200000434351
Appears in Collections:
GRADUATE SCHOOL[S](대학원) > MECHANICAL CONVERGENCE ENGINEERING(융합기계공학과) > Theses (Master)
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE