Effect of post-weld heat treatment on the wear resistance of hardfacing martensitic steel deposits

Abstract

The effect of different post-weld heat treatments on the microstructure and wear resistance of martensitic deposits were studied. The deposit was welded using a metal-cored tubular wire, in the flat welding position, on a 375 × 75 × 19 mm SAE 1010 plate, using 98% Ar–2% CO₂ shielding gas mixture and with an average heat input of 2.8 kJ/mm. The samples were heat treated at temperatures between 500 and 680°C for 2 h. Chemical composition, Vicker's microhardness and wear properties with AMSLER tests in a sliding condition were determined. In the as welded condition, the microstructure was principally composed of martensite and retained austenite. Significant variations in wear resistance and hardness were measured for different tempering temperatures. For the different heat-treated conditions, it was observed that the decomposition of retained austenite to martensite and carbide precipitation was associated with the tempering of martensite. A secondary hardness effect was detected with maximum hardness of 710 HV for 550°C heat treatment temperature. The best performance in wear test was obtained for this condition. Wear rates for the different conditions were obtained and mathematical expressions were developed. For each case, wear mechanisms were analyzed.

Keywords:

• hardfacing
• martensite
• post-weld heat treatment
• AMSLER wear test

Acknowledgements

The authors would like to thank Eutectic-Conarco for the provision of the consumable used, ESAB Brazil for the production thereof, developed especially for this work, Air Liquide Argentina for the donation of the welding gases, the Industrial Applications Workshop of Conarco-Esab for the welding facilities, Conarco-Esab for the realization of the chemical analyses, the Electron Microscopy Laboratory at INTI-Mecánica for the realization of the scanning electron microscopy, the Amorphous Solids Laboratory for the diffraction spectra and APUENFI (Association of Entrepreneurs-Teachers in the Mechanical Domain of the FI-Universidad Nacional de Lomas de Zamora) for its economic support for the present project. They would also like to acknowledge the ANPCyT for its financial support.

Notes

^1. [email protected]

^2. [email protected]

^3. [email protected]

^4. [email protected]

Additional information

Notes on contributors

Agustín Gualco

1. 1. [email protected]

Hernán G. Svoboda

2. 2. [email protected]

Estela S. Surian

3. 3. [email protected]

Luis A. de Vedia

4. 4. [email protected]