APPLYING A PERIPHERAL COATING TO AWS E FeCr-8 ELECTRODES TO IMPROVE THE RESISTANCE TO ABRASIVE WEAR

Abstract

Introduction:
White castings with a high Cr content of the hypoeutectic type are one of the most used in hardfacing to reduce wear by abrasion, in parts used in mineral processing, and in the sugar industry.
Objective:
To know the effect of a peripheral coating with a high C content, applied to a commercial AWS E FeCr-A8 electrode, on the microstructure of the deposited metal, as well as the behavior of resistance to abrasive wear.
Materials and methods:
Specimens were prepared for the characterization of the metal deposited with the original electrode (EO) and the modified one (EM) by means of hardness, optical metallography (OM), and analysis of the chemical composition using scanning electron microscopy (SEM). Using the test proposed by the ASTM G65, (2017) standard the resistance to abrasive wear was determined.
Results and Discussion:
The hardness of the metal deposited with the original electrode is 560 HV, while the hardness reached with the modified electrode reaches 750 HV, which is due to the fact that the morphology of the austenite and the eutectic zone is different for both deposits. The test of resistance to abrasive wear for the deposit obtained with the modified electrode showed a volume loss of 0.0531 mm3, lower than that manifested by the deposit made with the original electrode (0.0669 mm3).
Conclusions:
By applying a peripheral coating to the AWS FeCr-A8 electrode, the volumetric fraction of carbides in the eutectic zone of the deposit microstructure increases, improving the resistance to abrasive wear.