Study Of Mechanicals On Cryogenic Cold Air Turning Alloy Steel

With the people's enhanced awareness of environmental protection and increasingly strict environmental law, it's an important subject in the new century to carry out the "Green Project" and develop "green manufacturing technology". The cryogenic cold air cutting representatively the semi-dry cutting has become one of the hot areas of research in modern manufacturing industry. In this dissertation, on the current status and characteristics analyzing of such green cutting technology at home and abroad, the systematic research has been carried out on the effect that the cryogenic cold air cutting technology act on turning alloy steel. By comparing experiments on the dry normal temperature cutting and the dry cold air cutting, cutting chip, wear of the cutting tool and the roughness of machined surface have been systematically researched. In addition, the effect that the temperature of the cryogenic cold air acts on the wear of tool has been discussed. The results are as follows:①It's found that the critical feed-rate and the critical back engagement under the cryogenic cold air cutting are always less than that under the dry normal temperature cutting. Besides, compared to the area of chip-breaking under the dry normal temperature cutting ,the area of chip breaking under the cryogenic cold air cutting has been enlarged on small feed and small depth–cut. Therefore, from processing steel to consider, the cryogenic cold air cutting can made the chip more accepted and is more suitable for semi-finished, finished in term of turning the alloy steel.②The high-pressure cryogenic air can reduce effectively the temperature of the cutting area, restrain the Build-up edge's generation and prolong the tool life. With the high-speed steel tool turning 20CrMnTi, it can be seen that the cutting distance using the cryogenic cold air cutting is 4.16 times as long as that using the dry normal temperature cutting in the same conditions as well as the same wear standards. In other words, the distance life using the cryogenic cold air cutting is 4.16 times as long as that using the dry normal temperature cutting in cutting 20CrMnTi.③When the temperature dropped to a certain extent, the change of the flank wear is very small under the cryogenic cold air cutting. Therefore, the temperature of the cryogenic cold air should be reduced to a certain extent under the cryogenic cold air cutting.④The cryogenic cold air cutting can make the roughness of machined surface lower, but its effect is different by the nature of the materials. Generally speaking, it will have better results using the cryogenic cold air cutting for those materials that have big changes in low-temperature impact toughness.From the experiments, it can be obtained that the replacement of traditional cutting with the cryogenic cold air cutting can achieve to reduce pollution and protect the environment in certain conditions.