Surface strengthening method has become an effective way to realize the long life of bearings at home and abroad. Its technological method has developed from modern surface technologies such as laser, electron beam and ion beam to exploring the application of nano multifunctional mixed component materials to the working surface of bearings, so as to realize surface engineering technology with excellent comprehensive properties such as rust prevention, corrosion resistance, low friction coefficient, high hardness, high temperature resistance, wear resistance and impact resistance.
Metal wear self-repairing technology (hereinafter referred to as ART) can realize surface engineering technology with excellent comprehensive performance at the same time. It is a kind of ultrafine powder and a dynamic nano-scale action mechanism. This new intelligent self-repairing technology has completely changed the field of surface engineering. It will bring new opportunities for improving the life and reliability of bearings and contribute to improving the comprehensive strength of equipment manufacturing industry.
1 and introduction of ART technology
1- 1: Art technology is a patented technology with independent intellectual property rights.
Art technology is a submicron mineral powder composition, which is composed of complex components of hydroxysilicate. After several years of unremitting efforts, China engineers and technicians have made use of China's mineral resources for technological innovation and improvement.
In 2002, he was granted a national defense patent in China.
In February, 2009, we obtained the national patent in China.
1-2: art products
ART technology is a platform technology that integrates three functions of "anti-wear, anti-wear and in-situ self-repair". Beijing Weishi Alte New Technology Co., Ltd. has developed "Okmo" brand 19 series products according to different friction conditions.
Its modern art powder preparation equipment and first-class testing center can not only meet the needs of the domestic market, but also exceed the quality of similar products abroad. In order to verify the application effect of this product in actual working conditions, the bearing life extension test of ART rolling mill has been carried out on the hot rolling production line of Baotou Steel since 2008. By coating "Okmo" on the friction surface of rolling mill bearing, one-year production test proves that the service life of rolling mill bearing has been improved by more than 1 times. See figure 1, metallographic structure of 646290 bearing roller in hot rolling production line of Baotou Steel.
According to MEF4A advanced metallographic microscope, there is an artistic cermet protective layer with a thickness of 0.006 mm on the friction surface of the rolling element. ..
It shows that under the combined action of impact and friction, the quality of ART powder is excellent, and the protective layer of cermet-like material is evenly and stably distributed, which fully meets the technical characteristics and indicators. This is different from various engine oil additives on the market.
The friction between metals is transformed into the friction between the cermet protective layer and the cermet protective layer. There is no doubt that the service life of bearings will be greatly improved.
1-3: Art and technology are supported by relevant state ministries and commissions.
The research and application of this technology has been concerned and supported by the relevant ministries and commissions of the country. On September 18, 2002, the former State Economic and Trade Commission directly presided over the national appraisal meeting of "Metal Wear Self-repairing Materials" with the Science and Technology Commission for National Defense, the Ministry of Science and Technology, the Ministry of Railways, the Ministry of Communications, the Ministry of Education and the State Environmental Protection Administration. The appraisal committee composed of experts such as Xu, Zhong Qunpeng, Ding Chuanxian and Zhang Fuze 17 unanimously agreed that the project passed the appraisal, and its main appraisal opinions are as follows:
Metal wear self-repairing material is a high-tech product with independent intellectual property rights and has the advanced level in the world. The successfully developed self-repairing materials for metal wear have broad application prospects and can promote the basic research in the field of surface engineering tribology in China.
At the same time, it can promote the upgrading of China's traditional industries and have a great impact on the development of China's national economy. "This high-tech product should be quickly transformed into productive forces"; The State Economic and Trade Commission listed art projects in the "2002-20 16 National Science and Technology Innovation Plan".
State Councilor Wu Yi personally inspected the appraisal meeting of the project, and experts are discussing the project.
1-4: the technical characteristics of art;
(1), the main feature of self-repairing materials for metal wear is to produce a wear-resistant ceramic protective layer on the metal friction surface.
(2) The self-repairing material for metal wear belongs to superfine powder material, and the worn parts can be repaired without disassembly under the normal use condition of the machine.
(3) The self-repairing material can selectively compensate the surface wear, and the growth thickness of the wear-resistant ceramic protective layer is directly proportional to the amount of ultrafine powder and the energy released by friction, which can be automatically adjusted.
(4) There is no obvious interface between the wear-resistant ceramic protective layer and the original metal surface.
(5) The wear-resistant ceramic protective layer reduces the friction coefficient by an order of magnitude compared with oil film lubrication.
(6) The wear-resistant ceramic protective layer has good wear resistance and corrosion resistance. As long as the shape of the protective layer is completely maintained, the service life of the parts can be prolonged without replacing the parts.
(7) The wear-resistant ceramic layer can not only compensate the gap and restore the original shape of the part, but also optimize the fit gap, which is beneficial to reduce mechanical vibration, noise and energy.
Test the thickness of the cermet protective layer generated on the inner wall of the cylinder.
The cermet protective layer formed on the cylinder surface of DF- 1 1 locomotive 063 diesel engine 15 was observed by scanning electron microscope. The results show that the cermet protective layer with a thickness of about 65438 00 μ m can be clearly seen under optical microscope and scanning electron microscope.
Scanning electron microscope image of protective layer on cylinder liner surface (backscattered electron image, metallographic sample preparation method, after corrosion)
1-5: artistic and technical indicators:
Wear-resistant ceramic protective layer has unusual mechanical and physical properties:
(1), the friction coefficient: μ 0.003 ~ 0.007 is one order of magnitude lower than that of oil film lubrication.
(2) Microhardness: Hv690 ~ 1 100 is one to three times higher than the original surface hardness.
(3) linear expansion coefficient; 13.6 ~ 14.2 tonggang.
(4) Impact strength: 50kg/mm2.
(5) High temperature resistance: 1575 ~ 1600℃
(6) Corrosion resistance: it will not corrode in high-humidity marine environment and acid-base medium.
(7) Electrical insulation: 1- 10μm electrical insulation layer.
Three-dimensional image of hardness detection of ART protective layer under atomic force microscope
Rockwell microhardness HV = 1 145 Atomic force microscope image of cylinder liner surface protective layer (3D)
Atomic force microscope image of cylinder liner matrix with Rockwell microhardness HV = 546 (3D)
1-6: Art application field;
ART technology can be applied to any part of mechanical wear: mining machinery, metallurgical machinery, petrochemical machinery, construction machinery, internal combustion engines, chains and bearings of automobiles, trains and ships. Rolling mill bearings, railway bearings, motor bearings, wind power bearings, low-noise bearings, precision bearings, etc. urgently need to use ART technology to extend their service life in bearing manufacturing.
2. Art pretreatment
2-2- 1 :ART pretreatment process test
2- 1- 1: Dalian zhenglong weishi metal wear self-repairing technology development co., ltd.-a professional company engaged in the research and development and application of art application technology. Based on the research concept of "microstructure determines performance", many artistic bench tests were carried out:
In August 2003, it passed the bench test of National Chain Quality Supervision and Inspection Center, which increased the service life of petroleum roller chain by 3.3 times.
In 2007, I did "ART6308 Bearing Bench Test" in Zhejiang Tianma Bearing Co., Ltd.;
After 1000 hours of continuous bench test, the measured clearance is 2-6 microns lower than that before the test, which shows that ART technology can automatically optimize the friction clearance and achieve the best fit.
◆ In 2008, the bench comparison test of National Bearing Quality Supervision and Inspection Center further proved that ART technology can obviously prolong the service life and reliability of bearings.
2- 1-2: art pretreatment method:
In this method, the processed bearing parts are placed in a medium containing ART materials, and a dispersed ART inoculation layer is formed on the surface of the bearing parts under the action of a vibration polisher. After being sheathed, it works under the lubrication condition of lubricating oil or grease containing ART, so that the ART inoculation layer is further transformed into a cermet-like protective layer, and the best friction coefficient and fit clearance are obtained.
2- 1-3: art pretreatment equipment
In order to popularize the mature application technology of ART pretreatment, "Dalian Zheng Long Polishing Machine Manufacturing Co., Ltd." developed and manufactured powerful LZD series and XL series patching agent circulating pretreatment polishing machines; WZD horizontal large-scale ART pretreatment machine can meet the requirements of ART pretreatment for bearings of rolling mills with diameter 1. 1 m, and provide stable and mature pretreatment technology, quality control methods and testing standards.
It can meet the technological pretreatment of rolling mill bearings with diameter1.1m.
2-2-2 :ART preprocessing principle
Formation process of 2-2- 1:ART inoculation layer
Under the metallographic microscope, there are criss-crossing "gullies" microprotrusions, pits and various defects on the metal surface. In the vibration pretreatment of finishing machine, under the action of exciting force, in the process of friction, impact and extrusion, the particles of art powder are still larger than the microprotrusions and pits on the friction surface of most substrates. After being brought into the friction interface, they are further ground and refined, and the pits and defects on the friction surface are cleaned up, which is ready for the implantation of the inoculation layer.
In the process of vibration, friction, extrusion and impact, the instantaneous flash point temperature caused by the tearing and fracture of the convex body makes the high-temperature abrasive particles wrapped by ART and implanted in pits or defects with low potential energy to form a inoculation layer. The torn or damaged convex part also forms an artistic protective layer under the action of friction, which needs to be repaired. In the whole process of ART pretreatment, the defects of metal matrix, such as depressions, grooves, microcracks and cavities, are all formed by ART inoculation layer.
The growth speed and thickness of ART inoculation layer are directly proportional to the energy released by friction, the content of ART powder in polishing machine and polishing time.
This is the bearing roller made of GCr 15 material, and the hardened and tempered hardness HRc62 is 62 degrees. The metallographic structure of the bearing roller after artistic polishing pretreatment is observed under MEF4A advanced metallographic microscope.
2-2-2: Function of ART Inoculation Layer under Working Conditions
Under the working conditions, especially the rolling mill bearings, under the impact and instantaneous overload, the dispersion inoculation layer plays the role of supporting seat. In the whole process of bearing running with load, the interface of ART protective layer is constantly changing, the compensation position is automatically selected, and the formed thickness is also automatically adjusted. When the energy released by friction decreases to a certain extent due to the decrease of friction coefficient, the ceramic protective layer stops growing and the self-repair process is completed. The cermet layer can not only compensate the wear gap, reduce the roughness value of the metal substrate surface and restore the original size, but also make the friction resistance tend to be evenly distributed, reduce vibration, save energy, and realize the repair of the geometric shape of the metal working surface of the substrate and the optimization of the fitting gap.
2-2-3: Further Transformation of ART Inoculation Layer under Working Conditions
During the use of the bearing, under the action of friction, relying on friction heat energy as the driving force, the ART inoculation layer reacts with the surface of the metal matrix to form a microcrystalline ceramic layer, which is bonded to the iron-based metal through chemical bonds. This microcrystalline ceramic layer can dynamically and continuously repair and compensate the wear of the friction surface of the metal matrix, thus achieving the purpose of prolonging the service life of the bearing.
3. The influence of 3.ART technology on bearing life and reliability.
3- 1: test source and purpose
Entrusted by Dalian Zhenglong Weishi Metal Wear Self-repair Technology Development Co., Ltd., the National Center for Bearing Quality Supervision and Inspection conducted a comparative inspection of several groups of deep groove ball bearings 6307 provided by the company. In order to test the influence of metal wear self-repair technology and ART light decoration pretreatment on improving the service life and reliability of rolling bearings.
3-2: Test Scheme
3-3: Sample Source
Randomly take 20 sets of samples from the same batch of bearings from the same manufacturer, leave them as they are, and take 40 sets of samples without any treatment. The inner and outer raceway, rolling body and cage of the bearing are pre-treated by ART with finishing machine and ART material, so that the microcrystalline ceramic inoculation layer is dispersed on the bearing surface. After that, they were combined and divided into group C and group D, and 30 groups of samples were randomly taken out by the same sampling method, leaving them unchanged without any treatment. Each group 15 was divided into E group and F group, and then 15 group samples were taken. The surfaces of inner and outer raceway, rolling body and cage of bearing are pretreated by polishing machine and artistic materials, so that a dispersed microcrystalline ceramic inoculation layer is formed on the surface of bearing parts, code G.
3-4: Test Conclusion
Through this test, it can be seen that the service life of inner and outer raceway, rolling body, surface and cage of bearing is not obviously improved by using metal wear self-repairing material as additive of lubricating oil or grease or using polishing pretreatment technology alone. The combination of these two technologies can obviously prolong the service life of bearings, and the oil lubrication test and bearing life ratio can be increased by more than three times. The reliability value is improved from 97.9% to 99.7%; The basic rated life test value of grease lubricated bearings and bearings is increased to more than 5 times, and the life reliability value is increased from 77.44% to 99.98%.
4. Test conclusion analysis
4- 1: The comparative test of bearings pretreated by ART technology in the National Center for Bearing Quality Supervision and Inspection shows that under the lubrication condition of ART lubricating oil or grease, the service life of bearings pretreated by ART can be obviously prolonged.
4-2: After ART pretreatment, the bearing parts have different transition periods from ART inoculation layer to cermet-like layer under different service conditions. This is in line with the principle of forming ART protective layer. These different conditions include: bearing speed, load, lubrication condition, temperature, particle size of artistic powder and its content in oil or grease, material of metal friction pair, surface quality and hardness, etc.
4-3: According to the test conditions specified in Test Specification for Life and Reliability of Rolling Bearings JB/T500 13-2000, the conclusion is fair and objective. It has guiding value in a broad sense; As far as the practical application conditions in the market are concerned, it is the comparative test conclusion drawn by the fatigue testing machine under specific conditions, and it cannot summarize all kinds of bearings under practical application conditions. It has been proved that the service life of friction pair can be obviously prolonged by single process treatment or single process lubricating oil or grease.
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd