Abrasion resistance and hardness evaluation of FCAW-S hard-facing following elevated temperature exposure

Abstract

Proprietary compositional blends were welded for hardfacing applications. The blends were subsequently heat treated at progressively increasing temperatures followed by testing using industry key performance indicators. Each blend was developed to be used as a self-shielded FCAW wire for high-amperage, high-productivity deposition. Heat treatment of each consumable was completed in three conditions: as-welded, 400 °C (750 °F), and 700 °C (1290 °F). Microstructural analysis complimented mechanical testing and included field-emission scanning electron microscopy, surface hardness (HV10kg), ASTM G65 Method A abrasion mass loss, carbide volume fraction analysis, and rotary impact testing. The results of hardness testing showed that there was a differentiated decrease in average surface hardness between the blends as the heat treatment temperature was increased. All surface hardness measurements met the stringent industry performance indicator of 600 HV10 minimum. ASTM G65 Method A abrasion testing was performed following each heat treatment. All blends had acceptable abrasion mass loss as-welded, after a 400 °C heat treatment, and after a second heat treatment at 700 °C. Rotary impact testing of the consumables was completed after high temperature exposure in accordance with the Alberta Oil Sands procedure. Microstructural comparisons of the blends showed performance-indicating variation to support the mechanical testing results.