Friction, wear, and cutting tests on 022Cr17Ni12Mo2 stainless steel under minimum quantity lubrication conditions

Abstract

This study analysed the permeation mechanism of lubricants and the influence of lubrication action on the cutting force and cutting temperature in the machining process using a minimum quantity lubrication (MQL) approach. Friction, wear, and cutting tests were carried out on 022Cr17Ni12Mo2 stainless steel under the conditions of dry cutting (DRY), MQL, and cold wind (COL), respectively. Results showed that, for the YG8/022Cr17Ni12Mo2 friction pairs, the friction coefficients were reduced by 44.8 and 11.3 % on average under COL conditions compared with those under DRY and MQL conditions, separately. The wear rate of the stainless steel under MQL conditions was 86.3 and 87.2 % less than those under DRY and COL conditions, respectively. The particles under MQL conditions can generate thin oxide films with the effect of reducing friction on the friction surface at a high cutting speed with high efficiency. In the low-speed cutting process, the wear losses of all the flank faces were small, felt wear was mainly found under DRY and COL conditions, accompanied by abrasive wear and oxidative wear; while abrasive wear and oxidative wear primarily happened to those tools under MQL conditions, together with felt wear. By contrast, in the high-speed cutting process, felt wear and diffusive wear play the same important role in overall tool wear under DRY and COL conditions while diffusive wear, oxidative wear, and abrasive wear contribute equally to the wear of tools under MQL conditions; the tool tips were not as severely worn.