Abstract 17-4PH stainless steel is widely used for applications of critical importance owing to its favorable property profile. However, the great mechanical performance of 17-4PH stainless steel is at the cost of its unsatisfied machinability. Exploring suitable cooling method becomes an effective way to improve its machinability. This study aims to explore the applicability and feasibility of oils-on-water (OoW), which is a hybrid cooling/lubrication technique, compared with minimum quantity lubrication (MQL) in the finishing turning of 17-4PH stainless steel mixed with different cooling media, namely, cryogenic air (CA, −50 °C) and liquid nitrogen (LN, −178 °C). A comprehensive investigation of the cutting temperature, cutting forces, tool wear characterization and surface quality were studied. The result showed that CA or LN mixed with OoW (CAOoW/LNOoW) achieved the lowest flank wear compared with CA or LN mixed with MQL (CAMQL/LNMQL). Besides, CAMQL had the lowest friction force and coefficient of friction, thus resulting in significant surface roughness, which diminished by 38.4% when compared with dry cutting. The greatest anti-abrasion capability was acquired under LNOoW, wherein the addition of water improved the strength and longevity of the lubrication layer. It was found that the anti-adhesion capacity of the cutting tool increased with the decrease in environmental temperature. Even at cryogenic environment, it is still vital to provide cooling and lubrication to the tool–chip interface for further improving cutting performance.

中文翻译：

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低温油对水与低温微量润滑对17-4PH不锈钢精车的影响

摘要 17-4PH 不锈钢由于其良好的性能特征而被广泛用于至关重要的应用领域。然而，17-4PH 不锈钢出色的机械性能是以它的可加工性不令人满意为代价的。探索合适的冷却方法成为提高其可加工性的有效途径。本研究旨在探讨混合冷却/润滑技术水包油 (OoW) 与微量润滑 (MQL) 在混合不同冷却方式的 17-4PH 不锈钢精车中的适用性和可行性。介质，即低温空气（CA，-50°C）和液氮（LN，-178°C）。对切​​削温度、切削力、刀具磨损特性和表面质量进行了综合研究。结果表明，与 CA 或 LN 与 MQL 的混合（CAMQL/LNMQL）相比，CA 或 LN 与 OoW 的混合（CAOoW/LNOoW）实现了最低的后刀面磨损。此外，CAMQL 具有最低的摩擦力和摩擦系数，从而导致显着的表面粗糙度，与干切削相比减少了 38.4%。在 LNOOW 下获得了最大的抗磨损能力，其中添加水提高了润滑层的强度和寿命。发现刀具的抗粘连能力随着环境温度的降低而增加。即使在低温环境下，为刀具-切屑界面提供冷却和润滑仍然至关重要，以进一步提高切削性能。此外，CAMQL 具有最低的摩擦力和摩擦系数，从而导致显着的表面粗糙度，与干切削相比减少了 38.4%。在 LNOOW 下获得了最大的抗磨损能力，其中添加水提高了润滑层的强度和寿命。发现刀具的抗粘连能力随着环境温度的降低而增加。即使在低温环境下，为刀具 - 切屑界面提供冷却和润滑仍然至关重要，以进一步提高切削性能。此外，CAMQL 具有最低的摩擦力和摩擦系数，从而导致显着的表面粗糙度，与干切削相比减少了 38.4%。在 LNOOW 下获得了最大的抗磨损能力，其中添加水提高了润滑层的强度和寿命。发现刀具的抗粘连能力随着环境温度的降低而增加。即使在低温环境下，为刀具 - 切屑界面提供冷却和润滑仍然至关重要，以进一步提高切削性能。其中水的加入提高了润滑层的强度和寿命。发现刀具的抗粘连能力随着环境温度的降低而增加。即使在低温环境下，为刀具-切屑界面提供冷却和润滑仍然至关重要，以进一步提高切削性能。其中水的加入提高了润滑层的强度和寿命。发现刀具的抗粘连能力随着环境温度的降低而增加。即使在低温环境下，为刀具 - 切屑界面提供冷却和润滑仍然至关重要，以进一步提高切削性能。