Development and Application of Tiger Brand Aluminum Hot Rolling Emulsion Lubrication Technology
2021-04-25
【China Aluminum Industry Network】 Abstract: Briefly introduce the research and development of Lumiling aluminum hot-rolling emulsion and the principle of lubrication technology, and the use of emulsion in the field of maintenance and management. Through the actual application of customer case presentation, show the excellent performance of Tiger brand aluminum hot-rolled emulsion. Hot-rolled emulsions run more efficiently, helping users improve the surface quality of their products and saving overall costs.
Keywords: Aluminium Hot Rolling, Lubrication, Emulsions Introduction Aluminum and aluminum alloy sheet strips are important basic materials for the development of the national economy. The production of aluminum foils and foils in China has formed a relatively complete production system. Aluminum hot rolling is also a key development direction of the aluminum processing industry in China in the future. Hot rolling production has been rising year by year. With the rapid development of domestic large-scale hot strip mills, not only the surface quality of the aluminum sheet after hot rolling is required to be good, but also the long service life of the hot-rolled emulsion is required and the daily maintenance cost is reduced. Therefore, the development of aluminum hot-rolled emulsions should pay particular attention to the thermal stability, chemical stability, emulsion particle size distribution, and emulsification technology, etc., in order to roll out better aluminum materials, while increasing production efficiency and reducing the overall The cost.
At present, most domestic aluminum hot rolling processing companies still use a foreign brand of hot-rolled emulsion. With the continuous deepening of the Tiger brand to the Chinese market, a number of core products have been gradually established. After many years of hard work, the Tiger brand R&D team has cooperated with a number of internationally-renowned additive companies and finally successfully overcome many technical problems in 2012. It has developed Tiger brand aluminum hot-rolled product series with international leading technologies. The successful launch of the month to the market broke the long-term monopoly of competitors in the aluminum hot rolling market.
In order to keep tigers always at the forefront of lubrication technology, Tiger Brand Petroleum in 2015 reached a long-term strategic partnership with Northwestern University, which is hailed as “the mother of Chinese petroleum elites,” adding momentum to Tiger’s long-term development. We will always uphold the business principles of honesty and trustworthiness, adhere to the business philosophy of win-win with our customers, and are determined to serve Tiger's high-quality aluminum hot-rolled products to our vast number of Chinese customers. 1. Development goals of aluminum hot-rolled emulsions 1.1 Hot-rolling mills Requirements for Al-thermoemulsions (1) Excellent lubricating properties Aluminum-alloy hot-rolled oils should have good lubricating properties, so that the rolling force fluctuations during the rolling process are small, and the quality of the plate after rolling is good, and no sticky aluminum or streaks appear. Defects such as black and black lines.
(2) Longer service life The cleaning and replacement of hot-rolled emulsions requires a lot of manpower and material resources. At the same time, due to the increasingly stringent cost of environmental protection regulations and disposal of waste emulsions, in order to reduce emulsion discharge and protect the environment, aluminum hot-rolled emulsions are required. The service life should reach 12 months or more.
(3) Application range of rolling temperature The wide aluminum hot-rolled emulsion should be applicable to all hot rolling mills with an inlet temperature of 250-600°C.
(4) The range of application of the rolling of the emulsion should be broad and at the same time, the aluminum alloy products of various series should be rolled, and there is no need to switch or adjust the concentration and other indexes of the rolling.
(5) Excellent cleaning performance ensures that the plate surface after rolling is clean, bright and free from residue.
(6) Keeping the racks clean and non-toxic Due to the high hot-rolling temperature and the harsh on-site operating environment, it is required to use environmentally-friendly and non-toxic additive raw materials to ensure that the racks after rolling are clean and the on-site operating environment is clean and harmless to the human body.
1.2 The basic technical parameters and indicators of aluminum thermal emulsions take into account the requirements of hot rolling of aluminum and determine the relevant reference and specific parameters, see Table 1.
Table 1, basic technical indicators of aluminum thermal emulsion
2. Development of Aluminium Hot Rolled Emulsion Hot rolling is the rolling of metals above the recrystallization temperature. Since the metal is not work hardened in the hot rolling process, it has higher plastic deformation and lower deformation resistance and can be deformed with less energy. The outstanding feature of hot rolling is that the rolling temperature is high, and the instantaneous temperature of the roll surface in the rolling deformation zone can be up to 500-600°C.
Aluminium hot rolling is a common processing method in aluminum processing. In hot rolling, aluminum hot rolling oil is usually first mixed into a certain concentration ratio of emulsion (usually used concentration: 3 ~ 5%). The emulsion is sprayed through the nozzle onto the roll surface. Under high temperature conditions, the stable state of the emulsion cup breaks, resulting in oil-water separation. At this point, the water plays a role of cooling, and the separated oil adheres to the surface of the roller and acts as a lubricant. It is through this oil-water separation characteristic that the emulsion plays a role in cooling and lubricating. In this way, it can not only prevent the roller from overheating and the adhesion of the aluminum material and the roller, but also facilitate the flushing of the aluminum powder and ensure the good surface quality and cleaning of the aluminum plate after rolling.
From the aluminum hot rolling process conditions can be seen:
Aluminum alloy hot rolling oil must have good emulsification stability and thermal stability: Because at high temperature conditions, emulsions are often easy to demulsification and precipitation of oil, affecting the lubrication of the emulsion and cooling performance;
Aluminium hot rolling oil should have a suitable friction coefficient: the friction coefficient is low, and the roll and the rolling piece are likely to slip during the rolling process and cannot be bitten; if the friction coefficient is too large, the surface of the roller may be adhered with a layer of aluminum chips. Although a good aluminum rolling process requires a small amount of aluminum powder aluminum soap adhered to the roller, if the amount of aluminum powder is too much, the aluminum powder will be pressed into the aluminum plate again and cause surface quality defects.
In order to meet the special requirements of aluminum hot rolling, in the development of aluminum hot rolling oil, mainly from the oily agent, emulsification system, extreme pressure anti-wear agent and other aspects to solve the lubrication problem.
2.1 Selection of Polyol Ester Type Oil Agent The oil agent molecules are oriented on the metal surface by physical adsorption or chemical adsorption under the action of polar groups to form a strong adsorption oil film. The surface of the metal that is in contact with the naked eye is actually 100 to 1000 nm concave and convex. Actually, only the convex portion is in contact with the surface, and these convex portions support the entire load. The oily agent dissolved in the lubricating oil reduces the direct contact portion of the metal surface, thereby reducing friction and reducing wear.
The mechanism of action, see Figure 1
Fig.1 Mechanism of Action of Oily Agent
The key to synthetic ester additives is the selection of suitable fatty acids and fatty alcohol compounds. The relationship between the number of carbon atoms of fatty acids and the film strength and friction coefficient is shown in Figure 2
Figure 2 The relationship between the number of carbon atoms of fatty acids and the film strength and friction coefficient
As can be seen from Figure 2, the friction coefficient and oil film strength of fatty acids are related to the carbon chain length of fatty acids. As the carbon chain length of fatty acids increases, the friction coefficient gradually decreases, and the oil film strength gradually increases; but after the carbon chain length is greater than 12 The change is smaller. It has been pointed out that saturated fatty acids have better ester lubricity than unsaturated fatty acids, such as stearic acid has better lubricity than oleic acid esters. Different fatty acid esters can be selected depending on the source of the raw material, the pour point of the product to be delivered, and the performance of the product.
The current polyol ester has been widely used. In addition to its excellent thermal stability and oxidation stability, polyol esters also have good viscosity-temperature characteristics, lubricating properties, and excellent low-temperature viscosity properties. Several polyol esters were synthesized using polyol esters of different structures and fatty acids of different carbon chain lengths. The lubricating properties and main physical and chemical properties of several polyol ester oils are shown in Table 2.
Table 2 Lubricating properties and main physicochemical indexes of polyol ester oily agents
As can be seen from Table 2, ester E has a higher PB
The value and Falex failure load indicate that the extreme pressure performance and anti-wear performance are good. At the same time, the pour point is low, and the residual carbon content is not high. It can meet the requirements of aluminum hot rolling, and ester E is selected as the oil agent for the development of the product.
2.2 Selection of Emulsifiers The main role of emulsifiers is to reduce the surface tension and thus turn the emulsion into a thermodynamically stable system.
Keep oil droplets as stable as possible: The emulsion must have a certain degree of thermal stability and chemical stability to ensure its cooling and lubricating properties.
In the laboratory, the non-ionic surfactants A, B and anionic surfactants C, D, and E were combined to prepare the emulsion system. The entire development was investigated from the following aspects: 24h floatation, emulsion stability index ESI, and emulsion particle size. The stability of the product was evaluated at the same time as the industrial test. The results are shown in Table 3.
Table 3 Effect of type and amount of emulsifier on emulsion stability and particle size
As can be seen from Table 3, the emulsified liquid system obtained by compounding emulsifiers A, C, and E in a ratio of 2:1:1.5 has a relatively stable emulsified state, and therefore, A, C, and E are selected in the developed product.
2.3 Selection of extreme pressure antiwear agent The temperature and pressure are very high during the hot rolling of aluminum. The pure mineral oil and oiliness agent can not guarantee its good extreme pressure performance, so it is necessary to add antiwear agent and extreme pressure agent. Commonly used extreme pressure agents generally contain sulfur, phosphorus, chlorine and other elements. Because the sulfur-containing extreme pressure agent forms chloasma on the surface of the aluminum plate, and chloride can cause corrosion on the plate surface, the aluminum hot rolling oil generally uses a phosphorus-based additive, which mainly represents a phosphate ester and a phosphite ester. The main characteristic of the phosphorus-based additive is its anti-wearing effect, i.e., the polishing effect. The melting point of the metal compound is between the chloride and the sulfide. In the laboratory, alcohols and phosphoric acid reagents were used to synthesize phosphate ester extreme pressure agents. P2O5 was selected as the phosphorylation reagent to control the ratio of phosphorylation reagent to alcohol, and the appropriate reaction temperature and time were selected to synthesize a novel phosphate ester for testing and to optimize a phosphate ester extreme pressure agent AP and two kinds of phosphorus. Extreme pressure agents T304, T306 and a commercially available fatty alcohol phosphate ester were evaluated for extreme pressure anti-wear performance on a four-ball machine and a Falexs tester. The results are shown in Table 4.
Table 4 Extreme Pressure Antiwear Properties of Extreme Pressure Agents
3. Application and maintenance management of tiger brand aluminum hot-rolled emulsion 3.1 Control of the stability of hot-rolled emulsion 3.1.1 Control of emulsion particle size In general, the large bite angle of rolling bite during hot rough rolling is large. Therefore, the emulsion is required to provide a relatively high friction force so that the rolling piece can be smoothly bitten in. It also needs a good load carrying capacity to meet the requirement of a large reduction volume, and at the same time, the emulsion needs to have a relatively strong cooling capacity. Therefore, in the hot roughing stage, the size of the emulsion needed for the emulsion is small, and the emulsion needs to be relatively stable;
In the hot finish rolling stage, the rolling temperature is already relatively low, the deformation resistance is increased, and the rolled parts are thin and sensitive to surface quality defects. Therefore, the requirement for the emulsion is to have a good lubricating ability and the lubricating film must have a high The carrying capacity. The hot-rolled emulsion has a large milk particle size, the emulsion needs to be relatively unstable, and the oil-water separation is good, so as to meet the requirements of high lubricating ability.
For the hot roughing/finishing single stand rolling mill, the emulsion needs to take into account both the cooling performance in the rough rolling stage and the high lubrication requirement in the finishing rolling stage, so the overall design of the emulsion formulation is in between, and the emulsion needs to be relatively stable. State, the size of emulsion particles is generally between 1.0 ~ 1.5u. See Figure 3
Figure 3, emulsion particle size distribution
3.1.2 Thermal separation:
Thermal separation refers to the amount of pure oil that is separated when the emulsion comes in contact with a hotter roll. Thermal separation is an important indicator to measure the lubricating performance of emulsion; good heat separation, more oil is separated, lubrication is better; poor thermal separation, less separated oil, poor lubrication, relatively cool Well, the emulsion is more stable.
The heat separation property mainly depends on the content of the emulsifier contained in the emulsion, the shear force of the emulsion box circulation pump, and the size of the emulsion injection pressure. It is also affected by the roll temperature and the emulsion temperature during rolling.
3.2 Tiger brand daily maintenance testing items and control indicators, see Table 5
Table 5 Routine Test Items and Control Specifications for Hot Rolled Emulsions
3.3 Routine Maintenance and Management Points of Tiger Brand Hot Rolling Emulsion According to the control indexes of the emulsions listed in Table 5 above, the emulsions are monitored and controlled, abnormalities occur, retests are performed in time, experimental errors are eliminated, and corresponding measures are taken in time. The sample should be representative of the sample (sampled at the nozzle) at a fixed time, fixed position, and if the result is abnormal, it must be resampled for review. Regularly monitor and record the emulsion temperature, generally maintained at about 55 degrees; the daily rolling oil product should be slowly added before the working pump, the level of the emulsion tank liquid level should be monitored, and the emulsion should be kept at a higher and stable level to run as soon as possible. And regularly add water consumption, it is better to use deionized water to supplement, regularly detect the conductivity of deionized water. On-site laboratory daily monitoring items: concentration, pH, conductivity, etc.; regular sampling sent for comprehensive analysis.
Avoid miscellaneous oil leakage; strengthen olein oil and filter.
4. Practical Application Case Introduction 4.1 Tiger Aluminum Hot Rolling Customer:
Ningbo Fubang Precision Industry Group Aluminium Factory Started Date: August 2014 Hot Rolling Mill: 1550MM Two-Roll Double-Curly Reversible Rough/Finished Rolling Mill Main Aluminium Hot Rolled Product Series: 1 Series, 3 Series, 5 Series, 6 Series Aluminium and alloy coils, sheet emulsion tank volume: 40 tons with liquid water: deionized water emulsion temperature: 50-55 degrees 2015 hot rolling production: 41,400 tons 2015 average emulsion ton consumption: 0.47 (kg/ton aluminum)
Overview:
Tiger Brand assisted Ningbo Fubang Aluminium Factory to strengthen the routine maintenance and management of the emulsion to make the emulsion operation and maintenance more effective. The use of a good emulsion ensured that the normal production of hot rolling was carried out, and the quality of the surface of the hot rolled coil was significantly improved. In particular, it has solved the surface quality problems such as black silk black lines that have been plagued for many years. While guaranteeing the output of hot rolling, the surface quality of hot-rolled products has been improved, and the daily added consumption of hot-rolled emulsion has also been significantly reduced, making Ningbo Fubon Really achieve the desired goal of cost reduction and efficiency increase.
4.2 Tiger Aluminum's other aluminum hot-rolled customers do not introduce one by one in Anhui, Jiangsu, Zhejiang, and Guangxi.
5. Conclusion Tiger's aluminum hot-rolled emulsion products have lubricating properties, outstanding cooling performance, good corrosion resistance of aluminum and alloys, and long service life, achieving the expected application goals.
The product application results of Ningbo Fubang and other customers showed that the tiger brand company's aluminum hot-rolled emulsion has stable performance, good surface quality after rolling, reduced customer's comprehensive use cost, and can fully meet the actual use demand of aluminum hot rolling production enterprises.
References 1, "Plastic processing of nonferrous metals" Yang Shoushan Beijing: Metallurgical Industry Press, 1988.81
2. “Metal Processing Lubricants” Zhou Yaohua, Zhang Guanglin Beijing: Sinopec Press, 1998.173
3, "Lubricants and Lubrication" Manger. Dreser Beijing: Chemical Industry Press 2003.61
4. Wei Yunhua. Performance Control of Aluminum Hot Rolled Emulsion[J]. Light Alloy Processing Technology, 2002(10);14-15
5. Wang Chenghai, Liu Xiaojuan. Application Technology of Emulsion for Hot Rolling Aluminum and Aluminum Alloys[J]. Aluminum Processing, 2014(4); 27-31
G type of fin which is used in the industrial cooling unit , normally it is aluminum 1100 or 1060 sheet material. Aluminum coil thickness is regularly 0.3mm to 0.4mm temper HO.The fin will be wind on the extruded steel tube and made into cooling tower for heat transfer.The cooling unit is also called air cooling condenser.
Aluminum G type finstock strip is Trumony's strong product and we have exported this material to Asia,Middle East and Latin American countries.Quality feedback is very positive.Trust in Harmony.We care what our clients care.
Aluminium Stip, Aluminum Metal Strips, Aluminium Strip 1Mm, Anti Slip Aluminium Strips
Image Laser Technology Co., Ltd. http://www.szaluminumsheets.com