Fracture modes and acoustic emission characteristics of hydrogen-assisted cracking in high-strength low-alloy steel weldment



Document title: Fracture modes and acoustic emission characteristics of hydrogen-assisted cracking in high-strength low-alloy steel weldment
Journal: Journal of the Brazilian Society of Mechanical Sciences
Database: PERIÓDICA
System number: 000312013
ISSN: 0100-7386
Authors: 1
Institutions: 1Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Campinas, Sao Paulo. Brasil
Year:
Season: Dic
Volumen: 21
Number: 4
Pages: 675-682
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Experimental
English abstract The aim of the present paper is to study the relationship between the fracture modes in hydrogen-assisted cracking (HAC) in microalloied steel and the emission of acoustic signals during the fracturing process. For this reason, a flux-cored arc weld (FCAW) was used in a high-strength low-alloy steel. The consumable used were the commercially available AWS E120T5-K4 and had a diameter of 1.6 mm. Two different shielding gases were used (CO2 and CO2+5% H2) to obtain complete phenomenon characterization. The implant test was applied with three levels of restriction stresses. An acoustic emission measurement system (AEMS) was coupled to the implant test apparatus. The output signal from the acoustic emission sensor was passed through an electronic amplifier and processed by a root mean square (RMS) voltage converter. Fracture surfaces were examined by scanning electron microscopy (SEM) and image analysis. Fracture modes were related with the intensity, the energy and the number of the peaks of the acoustic emission signal. The shielding gas CO2+5% H2 proved to be very useful in the experiments. Basically, three different fracture modes were identified in terms of fracture appearance: microvoid coalescence (MVC), intergranular (IG) and quasi-cleavage (QC). The results show that each mode of fracture presents a characteristic acoustic signal
Disciplines: Ingeniería
Keyword: Ingeniería de materiales,
Ingeniería mecánica,
Ingeniería química,
Emisión de gases,
Hidrógeno,
Soldadura,
Fractura,
Acero
Keyword: Engineering,
Chemical engineering,
Control engineering,
Materials engineering,
Mechanical engineering,
Gas emissions,
Hydrogen,
Welding,
Steel,
Fracture
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