Tribological studies of some N, S, and Cl containing extreme pressure additives

Publisher Website
Google Scholar
Abstract
The antiwear and EP properties of certain p‐chlorophenyl groups containing nitrogen and sulphur open‐chain and cyclic compounds, in paraffin oil, were evaluated in a four‐ball test. The performance of the additives were compared with a commercially available sulphur‐phosphorus reference additive. All the additives, in general, exhibited good EP activity at different loads as compared to paraffin oil and the reference additive. However, the cyclic additives, e.g., 2‐phenyl‐3‐phenylimino‐5‐p‐Cl‐phenylamino‐1,2,4‐thiadiazolidine, and 2‐amino‐5‐p‐Cl‐phenylamino‐1,3,4‐thiadiazole, were found to possess good antiwear and EP properties in comparison to the plain paraffin oil, reference additive, and open chain additives. The wear surface tribochemistry and topography were studied using Scanning Auger Electron Spectroscopy (AES) and Scanning Electron Microscopy (SEM) techniques, respectively.A comparative EP activity evaluation of 1‐p‐Cl‐phenyl‐2,5‐dithiohydrazodicarbonamide and 3‐p‐Cl‐phenylimino‐5‐(N‐methylphenyl)amino‐1,2,4‐dithiazoline on steel bearing balls of different composition was undertaken to assess the suitability of replacing chromium alloy steel balls with cheaper carbon steel balls. The additive, 3‐p‐Cl‐phenylimino‐5‐(N‐methylphenyl)amino‐1,2,4‐dithiazoline exhibited its effectiveness on the alloy steel as well as low carbon steel bearing balls.A plausible explanation for the enhanced activity of additives is suggested and efforts made to correlate the effect of substituents and structure on the efficiency.