Abstract Surface roughness is one of the most common criteria indicating the surface finish of the part, which depends on various factors including cutting parameters, geometry of the tool, and cutting fluid. One of the goals of using cutting fluids in machining processes is to achieve improved surface finish. In addition to high costs, commonly used cutting fluids cause dermal and respiratory problems to the operators as well as environmental pollution. The present article aims at investigating the effect of spray cryogenic cooling via liquid nitrogen on surface roughness and cutting ratio in turning process of AISI 304 stainless steel. Through conducting experimental tests, the effects of cutting speed, feed rate, and depth of cut on surface roughness and cutting ratio have been compared in dry and cryogenic turning. A total number of 72 tests have been carried out. Results show that cryogenic turning of AISI 304 stainless steel reduces surface roughness 1%–27% (13% on the average), compared to dry turning. The obtained results showed that the cutting ratio in cryogenic turning is averagely increased by 32% in comparison with dry turning, also that chip breakage is improved in cryogenic turning.

中文翻译：

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喷涂低温车削加工表面粗糙度和切削比的试验研究

摘要 表面粗糙度是表示零件表面光洁度的最常见标准之一，它取决于多种因素，包括切削参数、刀具几何形状和切削液。在加工过程中使用切削液的目标之一是提高表面光洁度。常用的切削液除了成本高外，还会给操作人员造成皮肤和呼吸系统问题以及环境污染。本文旨在研究液氮喷雾低温冷却对AISI 304不锈钢车削加工表面粗糙度和切削率的影响。通过实验测试，比较了干车削和低温车削中切削速度、进给量和切削深度对表面粗糙度和切削比的影响。总共进行了72次测试。结果表明，与干车削相比，AISI 304 不锈钢的低温车削可将表面粗糙度降低 1%–27%（平均为 13%）。结果表明，与干车削相比，低温车削的切削率平均提高了32%，并且低温车削的断屑率得到改善。