Correlating Hardness and Welding Dilution with the Abrasion Mass Loss of Hardfacings Welded with Different Currents and Polarities
The correlation of hardness, microstructure, and dilution with the abrasion mass loss of hardfaced samples deposited using different currents (500 and 600 A) and polarities (AC and DC+) was studied. Four different welding conditions were considered for submerged arc welding using a martensitic hardfacing electrode and austenitic buffer electrode. Single-layer hardfacing was applied over the single-layer buffer. The microstructure of hardfacing was observed by an optical microscope. The micro-Vickers hardness across a single-layer hardfacing and dilution percentage were also measured. A dry-sand–rubber wheel abrasion test was conducted according to ASTM G65 procedure A to record the abrasive mass loss of the samples. The use of higher current and DC+ polarity resulted in the highest mass loss because of the deepest dilution and lowest hardness. Dilution affects the hardness and microstructure of hardfacing. The lowest abrasive mass loss, shallowest dilution, and highest hardness were obtained for the sample welded with lower current and AC polarity.
Keywordshardfacing martensitic austenitic buffer welding dilution submerged arc welding
This work was supported by the Higher Education Research Promotion and the Thailand’s Education Hub for Southern Region of ASEAN Countries Project Offi ce of the Higher Education Commission. The authors would like to acknowledge the Department of Mining and Materials Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai Campus, Thailand for supporting equipment, and the Electricity Generating Authority of Thailand (EGAT), Mae Moh Lignite Mine, Thailand for some data of this research.
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