Nucleation of Acicular Ferrite at Oxide Inclusion Sites in Basic Electrode Steel Metal Weld Deposits

摘要

The present investigation is concerned with basic studies of inclusion formation in SMAW weldments. This paper attempts to study the role of oxide inclusion sites on the transformation austenite→acicular ferrite in steel weld metal deposits. Properties of metal weld deposits depend on the amount of acicular ferrite in them. There is a special role for oxide inclusion sites on the nucleation of acicular ferrite. For good toughness over a range of temperatures, metal weld deposits should have a high amount of acicular ferrite. Different electrodes were used in order to obtain different as-deposited weld compositions. The microstructure of the welds with different oxygen levels, the inclusion size distribution and chemical composition of inclusions are characterized. Most observations and measurements were done with a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer.