Study on the effect of jet flow parameters with water vapor as coolants and lubricants in green cutting

PurposeAt the present time, green cutting has become the focus of attention in ecological and environmental protection. Water vapor is cheap, pollution‐free and eco‐friendly. Therefore, it is a good and economical coolant and lubricant. To find the discipline of nozzle diameter, the parameters of water vapor jet flow and cooling distance influence on its lubricating action effect, experiments were carried out in which YT15 (P10 type in ISO) tool was used in cutting C45 steel.Design/methodology/approachThe vapor generator and vapor feed system are manufactured. The temperature and velocity distribution of water vapor jet flow influences the velocity such that water vapor fills up the capillaries and forms the boundary lubricating film layer in the cutting zone, and the temperature and velocity distribution of the vapor jet flow section contains the effective area for the lubricating effect. Through the temperature distribution measured, the empirical formula of temperature distribution is obtained and simulated by Matlab. The turning experiment was carried out according to quantity in cutting υc=45, 60, 75, 90, 105, 120 mm/min, f=0.1 ∼ 0.3 mm/rev, ap=1, 2, 3, 3.5 mm and the jet flow parameters were changed, respectively.FindingsIt was found that: significant decrease of cutting force can be realized with reduced nozzle diameter, increased the sett pressure and shortened the cooling distance. However, reduced to a certain extent it will lead to the increase of the cutting force. The optimal nozzle diameter is 2 mm for the best lubricating effect. The effect on cutting force of the cooling distance is much better than the setting pressure. Significant decrease of friction coefficient of tool‐chip can be realized with reduced nozzle diameter. However, reduced to a certain extent it will lead to the increase of friction coefficient. Significant thinness of chips can be realized by reducing nozzle diameter. But if the diameter is reduced to a certain degree, chips will be thickened. Increased set pressure and shortened cooling distance can both reduce chip thickness, resulting in reduction of chip deformation coefficient. Since water vapor has the advantage of being cheap, pollution‐free and harmless, and there is no need for disposal and recycling, it is ideal for cooling and lubricating technology in green cutting.Originality/valueThe paper establishes the discipline of nozzle diameter, the parameters of water vapor jet flow and cooling distance influence on its lubricating action effect.