Wear Behavior of Hardfacings on Rotary Tiller Blades

Abstract

A rotary tiller is a mechanized agricultural implement popularly used to save time, human effort and fuel in preparation of soil bed. However, under complex abrasive environments, tiller blades are subjected to extreme surface wear, particularly in dry sand, which considerably affects its service life. The aim of this study was to improve the service life of the tiller blade in order to cut the idle time required to replace the blade periodically during cultivation. The aim was carried out by means of hardfacing, where the effect of the hard facings on the extent of wear and the wear characteristics of the tiller blades were examined. The influence of Cr is studied by hard facing of leading edge of tiller blades made of high tensile steel by gas tungsten arc welding using four different electrodes. The comparison of hard faced blades with un-hard faced (standard) blade was made through field and laboratory test. A field test was conducted on a 50 acre area of rice field after combine harvesting. During field test, rice stubbles were present and the condition of soil was dry and sandy. Different positions were selected for the test blades in the tiller to collect the meaningful data. The average wear rate of the un-hard faced blade was found as 7.08 gm/acre, while those of 5HCr, 7.5HCr, 12HCr and 8HCr hard facings were 5.02, 4.3 2.84 and 4.22 gm/acre respectively as indicated by field test results. A significant improvement was observed in the wear protection provided by hard facings over the un-hard faced blade.