Low hydrogen impermeable covered electrodes: Weld metal structure and properties

Conventional basic covered electrodes require special handling and storage conditions to avoid hydrogen cold cracking. In this paper were evaluated the weld metal microstructure and properties obtained by covered electrodes where the usual binders (sodium and potassium silicates) were changed by pol...

Full description

Saved in:
Bibliographic Details
Published inTecnologia em Metalurgia, Materiais e Mineracao Vol. 20110718; pp. 400 - 409
Main Authors Vaz, Claudio Turani, Felizardo, Ivanilza, Bracarense, Alexandre Queiroz, Pessoa, Ezequiel Caires Pereira
Format Journal Article
LanguageEnglish
Published 01.01.2011
Subjects
Covering
Diffusion
Diffusion welding
Electrodes
Ferrite
Hydrogen storage
Microstructure
Weld metal
Online AccessGet full text

Cover

More Information
Summary:Conventional basic covered electrodes require special handling and storage conditions to avoid hydrogen cold cracking. In this paper were evaluated the weld metal microstructure and properties obtained by covered electrodes where the usual binders (sodium and potassium silicates) were changed by polymers to make it impermeable. The weld metal was submitted to tension, impact (Charpy - V notch) and diffusible hydrogen testes and microstrutural evaluation. The microstructure showed the typical morphology and constituents. However, the grain boundary and aligned second phase ferrite volume fraction decreased and acicular ferrite fraction increased in comparison with same class conventional covered electrodes. The impermeable covered electrode weld metal diffusible hydrogen was considerable low in comparison with the conventional basic covered electrodes (less than 4ml/100g). The hydrogen content didn't increase after moisture exposition by long time period. The weld metal yield and tensile strength, elongation and impact toughness met the E7018 requirements.
Bibliography:ObjectType-Article-2
SourceType-Scholarly Journals-1
content type line 23
ObjectType-Conference-3
SourceType-Conference Papers & Proceedings-2
ObjectType-Feature-1
ISSN:2176-1515