Study of the welding procedure in nanostructured super-hard Fe- (Cr, Mo, W) - (C, B) hardfacing

GRAMAJO, J.; GUALCO, A.; SVOBODA, H.

INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS

ELSEVIER SCI LTD

Año: 2020 vol. 88

0263-4368

The optimization of the tribological properties of the surfaces by means of hardfacing techniques has made greatprogress in the metallurgical field in recent times. Alloys of the Fe-Cr-C and Fe-C-B type present excellent wearperformance under severe conditions, where the incorporation of Nb, Mo and W improves the performance ofsevere abrasive wear. In this context, new semi-automatic welding consumables have been designed that depositiron base material of high alloy, with complex carboborides of W, Mo and Cr which present very high hardnessand resistant to abrasive wear. The purpose of this work was to compare microstructural variations couponswelded with one or two layers, with or without shielding gas. The chemical composition was measured on eachcoupon, the microstructure was characterized by X-ray diffraction and scanning electron microscopy. Dilutionpercentage was determined and Vickers microhardness profiles (HV2) were made on the different phases(HV0.025). It was found that the dilution with and without shielding gas were 26% and 19%. The hardness was960 and 1100 HV2. An increase in hardness was observed in the recrystallized areas, as well as a higher percentageof carboborides in the last bead.