A Study on Machinability in Turning 1Cr18Ni9Ti Steel under Minimum Quantity Lubrication Machining

The present study show that metal cutting fluids changes the machinability because of their lubrication and cooling in turning 1Cr18Ni9Ti steel under minimum quantity lubrication (MQL) Machining. The experiments compares the mechanical performance of MQL to completely dry lubrication for the turning of 1Cr18Ni9Ti steel based on experimental measurement of cutting temperature, cutting forces, surface roughness, and dimensional deviation. Results indicated that the use of near dry lubrication leads to lower cutting temperature and cutting force, favorable chip-tool interaction, reduced tool wears, surface roughness, and dimensional deviation.

Properties of the Plasma Sprayed NiCrAlY+ (ZrO2+CaO) Graduated Coating on 1Cr18Ni9Ti Steel

The plasma sprayed gradated coating with the bottom layer of NiCrAlY and the top layer of (ZrO2+CaO) was prepared on the 1Cr18Ni9Ti steel surface by the plasma spraying technique. The phase structure and morphology of the gradated coating were analyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The high temperature oxidation resistance of the plasma sprayed samples at 800°C was investigated. The oxidation kinetics curve was worked out. The wear-resistance behavior of the graduated coating under dry sliding against GCr15 steel was evaluated on a ball-on-disc test rig. The results show that the thickness of gradated coating is about 320μm. The plasma sprayed gradated coating on stainless steel surface can improve the high temperature oxidation resistance of stainless steel. The oxidation rate of stainless steel is less than that of plasma sprayed gradated coating. The oxidation coating of plasma sprayed sample was very dense and is not easily exfoliated. The dense oxidation coating prevents the stainless steel from more oxidation. The friction coefficient of the 1Cr18Ni9Ti substrate was about 0.33 on dry sliding against the GCr15 steel, while the graduated coating experienced abated friction coefficient to 0.21 on the same testing condition.