1, transparent water-soluble cutting fluid
Formula 1(%) transparent water-soluble cutting fluid
Ethylene glycol 65.8; Sodium tetraborate 3.0; Sodium silicate1.0; Sodium phosphate 0.2; Water surplus.
This liquid is used for turning, grinding and drilling structural steel, and diluted by 3 times with water.
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* * * Three formulations.
2. Emulsified cutting oil
Formula 1(%) sodium petroleum sulfonate13; Polyoxyethylene alkyl phenol ether (OP-10) 6.5; Chlorinated paraffin10 ~ 30; Lead naphthenate 5; Triethanolamine oleic acid soap 2.5; High speed oil (No.5) balance.
This oil is used in extrusion, turning, drilling and other processes of metal processing, and its concentration is 5%~30% of emulsified oil.
Formula 2(%) sodium tall oil salt 4.5 ~ 5.5; 4.5-5.5 parts of sodium petroleum salt; C 1-4 synthesized 2.5 ~ 4 fatty acids; Polyethylene glycol1.5; Residual oil of industrial machinery.
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* * * Five formulations.
3, antirust extreme pressure emulsified oil
Formula 1(%) chlorinated paraffin10; Oleic acid sulfide 9; Barium petroleum sulfonate 20; Oleic acid 2; Triethanolamine 5; Residual machine oil (No.10).
This oil is mainly used for heavy-duty cutting and can replace vegetable oil and sulfurized cutting oil. The use concentration is 20%. Good antirust performance.
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* * * Two formulations.
4. Other cutting fluids
Formula 1 (parts) vulcanized cutting oil
Sulfurized cottonseed oil 500; Cottonseed oil1350; Sulfur 70; Mechanical oil (No.10) 2200.
Formula 2 ...
* * * There are four formulas.
Study on the formula of cutting fluid;
Water-based cutting fluid has excellent cooling and cleaning performance, but poor lubrication and rust prevention performance, so its application scope is limited. Nonionic surfactant H was synthesized from rosin, maleic anhydride and polyamine, and triethanolamine oleate was synthesized from oleic acid and triethanolamine. Practice has proved that the water-based cutting fluid composed of nonionic surfactant H and triethanolamine oleate has excellent lubricity, rust prevention, cooling and cleaning properties. It is a major breakthrough of water-based cutting fluid.
Modern machining is developing in the direction of high speed, strength and precision, and the development of ultra-hard and ultra-high strength materials makes cutting more and more difficult. These two reasons lead to the great increase of friction and friction heat in the cutting process, which requires the metalworking fluid to have better lubrication, cooling, cleaning and rust prevention performance in order to obtain an ideal machined surface. Mineral lubricating oil has excellent lubricating and antirust properties, but poor cooling and cleaning properties; Emulsion and water-based cutting fluid have excellent cooling and cleaning performance, but poor lubricating and antirust performance. In addition to all the properties of emulsion, water-based cutting fluid also meets or exceeds the standard requirements of emulsion in lubrication, cooling and rust prevention. Therefore, water-based cutting fluid has become the development direction of improving machining performance at home and abroad [l]. Adding oily additives and extreme pressure additives to water-based cutting fluid is an effective way to improve the lubricating and antirust properties of water-based cutting fluid. The nonionic surfactant H synthesized from rosin, maleic anhydride, polyamine and other raw materials has excellent lubricating and antirust properties, and trihexylamine oleate is an excellent oily additive. The water-based cutting fluid composed of nonionic surfactant H and triethanolamine oleate has excellent lubricating, antirust, cooling and cleaning properties. It is a major breakthrough of water-based cutting fluid.
1, synthesis of nonionic surfactant h
In the presence of catalyst, at the reaction temperature of 160 ~ 200℃, rosin [3] and maleic anhydride undergo a * * * polymerization reaction, and the * * * polymer further undergoes a neutralization reaction with polyamine to generate nonionic surfactant H, and the product is a reddish-brown viscous liquid. The infrared spectra of maleic anhydride, rosin and their polymers were determined experimentally, which proved the occurrence of the reaction.
Synthesis of Triethanolamine Oleate
Oleic acid is one of the important fatty acids with good lubricity, but it is insoluble in water. In order to add it to water-based cutting fluid, hydrophilic groups must be introduced into its molecular chain. Triethanolamine contains three OH groups in its molecule and can be esterified with acid [4].
At 130 ~ 160. Under the condition of C, when the initial molar ratio of oleic acid to triethanolamine is less than 1: 3, the COOH group of oleic acid reacts with the 10H group of triethanolamine to produce triethanolamine oleate, which is an excellent water-soluble oiliness agent. Tested by a four-ball machine, the maximum non-seizure load PB of 5% triethanolamine oleate aqueous solution can reach 700N, and its friction coefficient is 0.070 measured by MPV-200 friction and wear tester.
3 Formula and technological process of new water-based cutting fluid
(1) Formula of New Water-based Cutting Fluid
The new water-based synthetic cutting fluid developed by the author is mainly composed of nonionic surfactant H, triethanolamine oleate, extreme pressure antiwear agent, preservative and defoamer. Among them, nonionic surfactant H and triethanolamine oleate are synthesized by ourselves, and other components are commercially available. The distribution ratio of each group was selected through experiments, as shown in table 1.
(2) Process flow
The technological process of the new water-based synthetic cutting fluid is as follows:
Preparation of Nonionic Surfactant H Synthesis of Triethanolamine Monooleate —— Mixing, stirring, defoaming and canning all the components. 4 quality index of new water-based cutting fluid
According to the national standard (GB6144-85-85), the quality indexes of the new water-based cutting fluid are shown in Table 2.
4. Application results and theoretical analysis.
(1) Application result
After the successful development of the new water-based cutting fluid, it has been tried in Yuzhou Gear Factory and Dajiang Vehicle Factory successively, and satisfactory results have been achieved. On the whole, this product has the following characteristics:
1) has excellent heat dissipation performance. It can greatly take away the cutting heat, fully cool the cutting edge of the tool, and maintain its hardness, strength and sharp cutting ability, thus improving the working efficiency.
2) Excellent lubrication performance. Lubricating oil film can be formed in the cutting area, and the maximum non-stuck load PB value of cutting fluid can reach above 686 N N, so the cutting force can be greatly reduced and the consumption of tools and grinding wheels can be reduced. Compared with emulsified oil, the surface machining accuracy is significantly improved.
3) When in use, the lubricating cutting fluid will penetrate into the tiny cracks on the cutting surface of the workpiece, making the metal lattice on the surface brittle and easy to cut.
4) Good fluidity and cleanliness. Compared with emulsified oil, it can improve the smoothness of workpiece by L ~ 2 grades.
5) Excellent stability. When stored and used, it does not precipitate in layers, is not easy to rot, and does not produce gases that hinder workers' health. At the same time, the product does not contain sodium nitrite and mineral oil harmful to human body, so the working environment is clean and tasteless, and the surface of the workpiece can be clearly observed during processing.
6) Excellent chemical and thermal stability and rust resistance. Under high temperature and high pressure, it will not decompose, deteriorate or corrode the metal surface in contact with air. The processed parts will not rust for two weeks at room temperature.
7) The overall performance of the new water-based cutting fluid is equivalent to that of mineral oil, but the cost is less than half of that of mineral oil.
8) The new water-based cutting fluid has less working waste liquid and is easy to handle, which greatly reduces environmental pollution.
(2) Theoretical analysis
Lubrication performance analysis of 1)
In metal cutting, most friction belongs to boundary lubrication friction. In boundary lubrication, because there is no complete oil film, its bearing capacity has nothing to do with the viscosity of oil, but depends on the oiliness of lubricating fluid, that is, whether the lubricating component contains atoms with strong adsorption on metals.
Groups can form a physical adsorption film at the cutting interface.
The polar groups in nonionic surfactant H have great affinity for metals and are easy to adsorb on the metal surface to form an adsorption lubrication film. Because of its large hydrophobic group and aromatic ring structure, it has the function of oiliness agent. At the same time, nonionic surfactant H contains n inactive extreme pressure elements, which has the dual functions of oiliness agent and extreme pressure agent. Then it is matched with the added extreme pressure antiwear agent to form a high-strength physical and chemical adsorption film, which will not be destroyed under the action of high pressure, high temperature and fierce friction. It can prevent or reduce the direct contact between workpiece, chip and tool, achieve the purpose of reducing friction and adhesion, and play an excellent lubrication role.
Triethanolamine oleate is a cationic surfactant. When it is added to cutting fluid as an oiliness agent, it is easy to form a physical adsorption film between the tool and the cutting workpiece, thus playing a lubricating role. In addition, triethanolamine oleate and extreme pressure antiwear agent also have good synergistic antiwear effect, which can also significantly improve lubrication performance.
2) cleaning performance analysis
The cleaning performance of cutting fluid is closely related to the permeability and fluidity of cutting fluid. Cutting fluid with low surface tension, good permeability and fluidity has good cleaning performance.
Due to the existence of nonionic surfactant H and cationic surfactant triethanolamine oleate, the surface tension of the new water-based cutting fluid is greatly reduced, and the permeability and fluidity of the cutting fluid are obviously enhanced. Therefore, it has good cleaning performance.
3) cooling performance analysis
The cooling effect of cutting fluid depends on its thermal conductivity, specific heat, vaporization heat and vaporization speed. The thermal conductivity of water is 3 ~ 5 times that of oil, and the specific heat is 2 ~ 2.5 times that of oil, so the cooling performance of water is much better than that of oil. The water content of the new water-based cutting fluid is over 90%, and its cooling performance is outstanding.
4) Analysis of antirust performance
Non-ionic surfactant H itself has the function of rust prevention and corrosion protection, and has a synergistic effect with the added preservative, forming an adsorption protective film on the metal surface to passivate the film, thus blocking the corrosion process of anode and cathode. Because the coating is dense, it can effectively resist the penetration of corrosive substances such as water molecules and oxygen in the medium, and has excellent anti-corrosion and anti-rust performance.
5. Conclusion
(1) The nonionic surfactant H synthesized from rosin, maleic anhydride and polyamine has excellent lubricating, antirust and cleaning properties.
(2) Triethanolamine oleate is an excellent water-soluble oiliness agent.
(3) The water-based cutting fluid compounded by nonionic surfactant H and triethanolamine oleate has excellent lubricity, rust resistance, cooling property and cleaning property. It is a major breakthrough of water-based cutting fluid.