In modern machining, the hole with the ratio of processing hole depth to hole diameter greater than 6 is usually called deep hole. Deep hole drilling has uniform cutting force distribution, good chip separation and chip breaking performance, stable and reliable drilling, and good straightness of deep hole drilled. It is a link that can not be ignored in the development of machining.

1、Process analysis

During deep hole drilling, it is difficult to dissipate heat and chip, and the drill pipe is thin and rigid, which is easy to produce bending and vibration. Generally, the pressure cooling system is used to solve the cooling and chip removal. If the lubricating cooling medium is improperly selected, the following problems are easy to occur:

1. Heavy smoke

2. Chip removal is not smooth

3. Fast wear of drill bit

There are many kinds of deep hole drilling cutting oil on the market. Compared with traditional cutting oil, the formula is basically the same, but the viscosity is different. It is necessary to scientifically analyze the processing characteristics of each process and clearly understand the action mechanism of the three extreme pressure and anti-wear additives of chlorine, phosphorus and sulfur, so as to develop strengths and avoid weaknesses and accurately apply them in various metal processing processes. Although deep hole drilling belongs to cutting technology, it is different from traditional cutting. In practice, it is found that when traditional cutting is processed, multiple cutting tools work at the same time, and the torque of each process is different. In the early stage of deep hole drilling, as soon as the drill bit contacts with the workpiece, the pressure reaches about 2000N and the temperature increases instantaneously. It is required that the selected oil has low viscosity, good permeability, good cooling and smooth chip removal; At the end of processing, the pressure is about 4000N. If the extreme pressure value (PD) of the selected oil is lower than 4000N or the release speed of extreme pressure agent in the oil is slow, it is inevitable to smoke and wear the drill bit quickly. Therefore, as long as the extreme pressure agent selected has low viscosity and high extreme pressure wear resistance, the "yidaboren linear theory" is applied, Test whether the oil can be released quickly in the key range of 2000n-4000n.

2、Selection of additives

With the continuous development of metal processing technology, the dominant position of vulcanized extreme pressure anti-wear additives in the field of metal processing oil is becoming more and more obvious. Vulcanized extreme pressure anti-wear additives that can meet the requirements of deep hole drilling technology are rare. After many years of experience in the application of yz-30b as well as the analysis of the sulfur ester, yz-30b is an ideal cutting agent for the deep drilling of BofA and Sinopec.