Abstract
Super duplex stainless steel, which is one of the difficult-to-cut materials to machine, is excellent in toughness at room temperature and corrosion resistance. It is used in many applications, such as marine structure and petrochemical plant. However, this stainless steel has certain material characteristics, such as low thermal conductivity, a high work hardening rate, and a high affinity to tools. In this study, the tool wear of coated cemented carbide tool is investigated in turning of super duple stainless steel at three different cutting environments of Wet, MQL and micro dry ice powder supply method. In the three different environments at cutting speed 2.0 m/s, the adhesion were confirmed on the rake face of all cutting environment conditions, the tool life was determined by failure due to different factors. In Wet condition is failure at cutting length of 5.0km due to the irregular formation of adhesion on the cutting edge. In MQL condition, it is possible to suppress the adhesion on the rake face by the lubricating effect, but the side boundary wear causes the failure. In addition, it was found that the side boundary wear can be suppressed under the DIPS condition, but the flaking damage of the rake face wear is remarkable. In the case of the hybrid supply method of DIPS and MQL, it was found that the side boundary wear and the adhesion on the rake face can be suppressed, and the stable cutting edge is kept even at the cutting length of 5.0 km.
