The Effect of Machining Fluid in the Process of Steam-Treated Pine and Beech Wood Turning on Selected Surface Roughness Parameters

In this study, the influence of different cutting conditions on the quality of the machined surface during the turning process of steam-treated pine wood (Pinus sylvestris L.) and beech wood (Fagus sylvatica L.) was investigated. The cutting conditions analysed included dry turning, turning with compressed air cooling, and turning with oil mist cooling. The turning processes for all analysed cutting conditions were carried out for three different feed per revolution values. The carried out studies allowed the observation of a noticeable increase in the values of the analysed surface roughness parameters (Ra, Rz, Rq, Rt, and Rp) with the increase in feed per revolution for pine and beech wood. In addition, a noticeable decrease in the values of these parameters was observed with the use of compressed air and oil mist (MQL) for pine wood. However, in the case of beech wood, the lowest surface roughness values were observed during dry turning, while the use of MQL leads to increased values of surface roughness, especially at high feeds per revolution.