Acta Univ. Agric. Silvic. Mendelianae Brun. 2014, 62, 1161-1169

https://doi.org/10.11118/actaun201462051161
Published online 2014-12-02

Application of Hard Metal Weld Deposit in the Area of Mixing Organic Materials

Jiří Votava, Vojtěch Kumbár

Department of Technology and Automobile Transport, Faculty of Agronomy, Mendel University in Brno, 613 00 Brno, Czech Republic

Any machine part is subject to degradation processes. Intensive wear occurs either when two bearing surfaces come into contact or when loose particles rub the function surface of a machine part. Soil processing machines are a good example. A similar process of abrasive wear occurs also in mixing machines or lines for material transport, such as worm-conveyors.
The experiment part of this paper analyses hard metal weld deposit dedicated for renovation of abrasive stressed surfaces. In order to prolong the service life of a blade disc in a mixing machine Kreis-Biogas-Dissolver, the technology of hard surfacing by an electric arc was used. Tested hard metal electrodes were applied on a steel tape class 11 373. To eliminate mixing with the base material, weld beads were applied in two layers.
Firstly, the weld bead was visually analyzed on a binocular microscope. Further, weld bead as well as the base material was analyzed from the metallographic point of view, whose aim was to identify the structure of weld metal and the origin of microcracks in weld bead.
Moreover, there was also measured microhardness of weld metal. Abrasive resistance was tested according to the norm ČSN 01 5084, which is an abrasive cloth test. As in the mixing process also erosion wear occurs, there was also processed a test on a Bond device simulating stress of test samples by loose abrasive particles. The abrading agents were formed by broken stones of 8–16 mm in size. Based on the results of the individual tests, the recommendation of usage hard metal electrodes for prolonging service life of machine parts will be made.

Funding

This study was supported by the project No. TP 4/2014 “Analysis of degradation processes of modern materials used in agricultural technology”.

References

19 live references