A study of the influence of steam treatment on the tribological behaviour of steel specimens

The influence of steam treatment (ST) on the tribological behaviour of steel was assessed by Falex, Schwingungsreibverschleiss (SRV) and Amsler tests performed either under dry conditions or using solid MoS₂, graphite, polytetrafluoroethylene (PTFE) or grease lubricants. ST produced a thin layer of magnetite containing small quantities of haematite. MoS₂ was found to be the best lubricant in Falex tests with normal test pieces. Only greaselubricated Amsler couples withstood the full testing cycle. The SRV tests were inconclusive because the endurance time was too short, only a few seconds with MoS₂ lubrication.The influence of ST varied in the Falex tests. No improvement was found with grease-lubricated journals and the load-carrying capacity of MoS₂-lubricated test pieces was decreased. However, it was beneficial for PTFE lubrication. In the Amsler tests the grease-lubricated disks were crazed and magnetite splinters were removed. The performance of the graphite lubricant was lowered by ST and the median lives of MoS₂- or PTFE-lubricated couples were increased although their reliability was impaired. In SRV tests, ST improved the performance of grease and MoS₂-lubricated test pieces. The test results do not confirm the reported improved behaviour of ST components, particularly cutting tools, in workshop practice.