Evaluation of Microscopic Damage to TIG Welded Carbon Steel using Acoustic Emission and Ultrasonic Test

doi:2012.26.5.5

J. Ocean Eng. Technol. > Volume 26(5); 2012 > Article

J. Ocean Eng. Technol. 2012;26(5):5-10.
DOI: https://doi.org/10.5574/KSOE.2012.26.5.005

Lee Joon-Hyun,Lee Jin-Kyung

School of Mechanical Engineering Pusan National University,Department of Mechanical Engineering Dong-Eui University

음향방출과 초음파를 이용한 TIG 용접탄소강의 미시적 손상평가

이준현,이진경

부산대학교 기계공학부,동의대학교 기계공학과

Keywords: A53 Carbon Steel, Weld, Acoustic emission technique, AE parameter, Events, Cumulative count, Amplitude

핵심용어: A53탄소강, 용접, 음향방출기법, 음향방출 파라미터, 사상수, 축적카운터, 진폭

Abstract

In this study, carbon steel (A53) is used as the material for the pipes in a marine plant and ship industry. Welds are necessary to join the carbon steel, and the effect of this welding on the properties of the carbon steel has been studied by many researchers. In this study, the dynamic behavior of welded carbon steel was studied using an acoustic emission (AE) technique, which is a nondestructive test. There are numerous AE parameters that can be used to analyze the damage behavior of carbon steel by external loading. The AE parameters of energy, cumulative count, amplitude, and AE event were used, and each parameter was differentiated according to the degree of damage to the carbon steel. The energy showed a high level at the elastic range of the load curve, while the amplitude had the highest value at the hardening region. The cumulative count showed a growth tendency similar to the loading curve. In addition, an ultrasonic technique and hardness test were applied to evaluate the mechanical properties according to the base zone, HAZ region, and weld zone of the weld specimen. The velocity and attenuation ratio showed little change between zones, and an evaluation of the ultrasonic waves on each zone of the specimen was found to be a useful method to clarify the mechanical properties of the carbon steel.