Determination of the uncertainty of microhardness in the evaluation of hardfacing obtained by welding

[摘要] The present work evaluates the microhardness measurement uncertainty using a Vickers indenter in the characterization of hard deposits, obtained with experimental electrode for hardfacing of cutting knives in sugar mills. The following stages were proposed: i) obtainment of the deposit with experimental electrode, ii) obtainment of the samples, iii) chemical characterization, iv) metallographic analysis, v) microhardness measurement and vi) uncertainty measurement assessment. It was observed that the obtained deposit presents chrome carbides and eutectic matrix composed of austenite and carbides. The expanded uncertainty associated to the microhardness measurement is highly influenced by the low repeatability of the obtained microhardness values.

[发布机构] Central University Marta Abreu of Las Villas, Research Center of Welding, Road to Camajuaní 5 1/2 km Santa Clara, Villa-Clara, Cuba^1;Federal University of Uberlândia, Campus Santa Mônica, João Naves de Ávila Avenue, 2121, Uberlândia MG; 38400-902, Brazil^2;University of Brasília, Faculty of Tecnology, Department of Mechanical Engineering, University Campus Darcy Ribeiro, Asa Norte, Brasília, DF; 70910-900, Brazil^3

[效力级别] 力学 [学科分类] 力学，机械学

[关键词] Chemical characterization;Cutting knives;Eutectic matrix;Experimental electrodes;Metallographic analysis;Microhardness measurement;Uncertainty measurements;Vickers indenters