Sustainable grinding: mitigating CO2 emissions through MQL+WCJ technique in AISI VP50 steel processing

In plastic mold injectors, VP50 steel stands out as one of the most used materials. Their application demands high mechanical strength to ensure the repeatability of plastic production. VP50 steel possesses exceptional wear resistance and easy machinability, making it an indispensable choice for mold steels. Therefore, it is common to grinding this material to obtain the specified tolerances. In machining processes, cutting fluid presents itself as a fundamental component, as they are responsible for the refrigeration and lubrication of the cutting interface. However, cutting fluids are emulsions of water and mineral oil composed of hydrocarbons derived from petroleum refining, which, when burned, can release CO2, contributing to the strengthening of the greenhouse effect. Considering the consequences of global warming and the future of humanity due to CO2 emissions, the United Nations (UN) established an agenda called Sustainable Development Goals (SDGs) to be achieved by the year 2030. Aligning the SDGs with the setbacks present in the lubrication-cooling technique in the grinding process, alternative options arise, as well as the minimum quantity of lubricant (MQL) and the wheel cleaning jet (WCJ) system. This research analyzes the grinding behavior of VP50 steel. For this, techniques are used comparatively, conventional flood, pure MQL, and MQL+WCJ. Analyses are performed under three feed rate regimes, 0.25, 0.50, and 0.75 mm/min, obtaining the following output parameters, surface roughness, roundness error, diametrical wheel wear, G-ratio, grinding power, acoustic emission, cost, and pollution. The results obtained in this paper show the great industrial applicability of MQL, with and without WCJ. Thus, the results showed that different machining techniques and materials could be used to minimize the use of cutting fluid.