Influence of Surface Hardening with Carbon Nanotubes-Hard Chrome Composite on Wear Characteristics of a Simple Tillage Tools

The objective of this study was to reduce wear behavior of soil working tools by coating and treating processes of the tool surfaces. Three different carbon steel materials: API 52, M238 and K110. Some of the previous specimens were treated with two different coating materials: Hard chrome, HCR, and carbon nanotubes- hard chrome composite, CNTs + HCR. The other specimens were treated by: conventional heat treatment, HT, and nirtocarborizing treatment, NC. Both the coated and treated tool specimens were mounted on a circular soil bin containing sandy clay loam soil at 14% moisture content. The working speed was adjusted at 5 km/h (1.39 m/s). The coating thickness and the mass of tools were measured before and after each test. The test duration of tillage operation was conducted for 200 h for both coated and treated tools. Results obtained from all tests showed that, the wearing rate of coated specimens by carbon nanotubes-hard chrome composite CNTs + HCR were the minimum compared with other treatments. Results also showed that the surface roughness was the minimum.