Research on Lubrication Behaviors and Mechanism of Nano-Copper Used in Emulsions for Strip Cold Rolling

In this paper,nano-Cu particles with an average size of smaller than 20 nm were dispersed under ultrasonic agitation in emulsions for cold rolling of steel strips.The tribological properties of the cold rolling emulsion doped with nano-Cu particles were evaluated by using a four-ball machine,and the worn surfaces of the steel balls were checked by an optical microscope.A JC2000C1 wetting angle tester was also applied to study the variation in the emulsion’s wetting performance when nano-Cu particles were incorporated.Furthermore,the lubricity of the emulsion doped with nano-Cu for steel strip cold rolling was evaluated on a four-high rolling mill for comparison with the emulsion without using nano-Cu particles.Test results indicated that nano-Cu particles as the additive used in cold rolling emulsion were able to improve the wetting property,friction-reducing,anti-wear,and extreme pressure performance of the base stock significantly.At the same time,nano-Cu particles also showed good lubricity to the cold-rolled steel strips.Namely,the cold-rolled steel strips under the lubrication of the cold rolling emulsion containing nano-Cu particles had considerably decreased the after-rolling thickness and achieved excellent surface quality as well.Finally,the lubrication mechanism of nano-Cu particles in the emulsion for cold rolling of steel strips was discussed.     

纳米MoS2在钢冷轧轧制液中的摩擦润滑性能研究

The nano-MoS2 particles were adopted to substitute for the extreme-pressure and anti-wear additives to the rolling fluid for steel strips.An optimal formulation and technical process for adding nano-MoS2 particles to the rolling fluid were obtained through orthogonal experiments with three factors at three levels.The tests have led to the following conclusions:(a) the nanoparticles should be added to a base oil with high saponification value;(b) the concentration of nanoparticles in rolling fluid should be equal to 0.6%;and (c) when the reaction time needed for surfactants (oleic acid,for example) to modify the nanoparticles was 40 min,the rolling fluid could have the best tribological properties.The lubricity of rolling fluid was verified by using a 4-high cold rolling test mill which showed that the rolling fluid with nano-MoS2 particles had the excellent lubricant performance to improve the surface quality of the steel strip remarkably.The mechanism of nano-MoS2 particles in the rolling process has been investigated by a series of characterization instruments,which have showed that,with its fullerene-like structure,the nano-MoS2 particles have self-lubricating properties and extra-low friction coefficient,and can easily form a protective film with low shear strength on the surface of friction pairs.     

Synthesis of Two Novel Additives and Study of Their Tribological Properties in Rapeseed Oil

Two novel ashless additives - benzothiazole derivatives containing boron and chlorine, OBC and BBC, were synthesized. The tribological performances of OBC and BBC at different mass ratios as additives in rapeseed oil （RO） were examined on a four-ball machine. The worn surfaces of the lower steel balls lubricated by oil samples were analyzed by means of scanning electron microscopy （SEM）. The test results showed that OBC and BBC had good solubility in the base oil, and could effectively increase the load-carrying capacity of the base oil. The maximum non-seizure load of oil sample containing 1.5 m% BBC was 1117 N, which was 2.3 times as much as that of the base oil. Both OBC and BBC could improve the anti-wear and corrosion inhibiting performance and thermal stability of the base oil, whose initial decomposition temperatures was above 350 ~C. However, OBC and BBC at different concentrations could increase the friction coefficient of the base oil. The SEM morphology of steel balls lubricated by oil samples containing 1.5 m% additives seemed to be more uniform and smoother than that of the base oil, and the scars formed were very shallow.     

一种防卡咬螺纹润滑剂的理化和摩擦学性能研究

Di-aromatics base oil and graphite powder, adding with viscosity index improver and anti-oxidant and rheological additive, were used to prepare a kind of anti-seize thread lubricant. Its physical chemistry properties, such as water resistance, thermal oxidation and aging properties, tribological performance were evaluated and compared with those of some commercial product. The results show that the overall the overall performance of the anti-seize thread lubricant met the level of some commercial product, and some properties such as thermal stability, anti-wear and anti-friction properties were better. It is more suitable for high temperature conditions.     

PREPARATION AND RHEOLOGICAL PROPERTIES OF VACUUM GREASE

A kind of vacuum lubricating grease was prepared by using perfluoropolyether as base oil,perfluorinated polymer as thickener,and self-made additives.The colloidal stability of the grease was greatly improved by introducing a colloidal structure modifier.The rheological properties of the self-made grease(SMG),such as viscosity versus time,thixotropy,etc.,were studied by a rheometer at different temperatures and were compared with those of foreign brand grease(FBG).The results show that the performance of SMG reached the level of similar FBG,and some properties such as mechanical stability,colloidal stability,extreme pressure and antiwear properties were better.It can be used for long life lubrication of moving parts in a vacuum environment.     

矿物润滑油在薄膜润滑区域内的摩擦特性研究

On the basis of thin film lubrication theory, the influence of fluid film(disordered film), ordered film and adsorbed film on tribological behavior of lubricating oil in thin-film lubrication(TFL) regime was studied. The μ-L(friction coefficient versus load) curves of different oil viscosity and additive dosage were obtained by a high frequency reciprocating test rig and the adsorption capacity of additive on steel surface were measured by QCM-D. Based on the Stribeck curve and thin film lubrication theory model, some conclusions can be drawn up, namely:(1) The μ-L curves and the parameters of L0 and μ0, obtained from the high frequency reciprocating test rig with ball-disc contact, can be used to study tribological behaviors of lubricating oil under TFL conditions.(2) In comparison with the high viscosity base fluid, the lower one can enter into TFL regime under lower load and keeps a lower friction coefficient in TFL regime.(3) The polar molecules in additive formulation produce ordered adsorbed layer on steel surface to reduce friction coefficient. And in TFL regime, the molecule's polarity, layer thickness and saturation degree on steel surface probably can influence lubricant's tribological behaviors between the moving interfaces. Moreover, the further study would be focused on the competitive adsorption of different additives, the formation of dual- and/or tri-molecular adsorption layers, and other aspects.     

缓蚀剂对铜箔轧制油润滑效果的影响

The 2,5-bis（ethyldisulfanyl）-l,3,4-thiadiazole （T561）, benzotriazole （BTA）,1-N, N-bis （2-ethylhexyl） aminomethyl-4-methyl-lh-benzotriazole （IRGAMET39） and I-IN, N-bis （2-ethylhexyl） aminomethyl] methyl benzotriazole （TT- LX） have been evaluated as corrosion inhibitors used in rolling oil for cold rolling of copper foil. The MRS-10A four-ball friction and wear tests have been carried out to compare their tribological properties, and the lubricating performance of rolling oils has been studied through rolling experiments. The oil sample containing IRGAMET 39 has the same PB value as that one containing T561, with the coefficient of friction increased by 35.6% and wear scar diameter decreased by 4%. The minimum rolling gauge has been studied after rolling lubrication, but the results show that inhibitors have no effect on it. Scanning electron microscopy （SEM） and energy dispersive spectrometry （EDS） analyses have indicated that the inhibitor is adsorbed on the copper surface to prevent copper from being corroded easily. In addition, the LEXT OLS4000 laser confocal microscopy has been used to observe the foil surface which shows that the streaks of foil surface are clear, the scratches are shallow and the surface failure is improved effectively.     

Study on Tribology Performance of Different Lubricant Additives under Atmospheric Pressure and High Vacuum Conditions

By using PAO-10 as the base oil, the tribological behavior of 11 additives under high vacuum condition was evaluated. By adopting some surface analytical instruments, such as scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray photoelectron spectroscopy(XPS), the tribological mechanisms of these additives were studied. In air, O_2 can react with metal to form metal oxide that can protect the surfaces of rubbing pair during the tribological tests. According to the theory of the competitive adsorption, the function of some active elements is weakened. In a vacuum environment, the additives contributed more to the lubrication performance. The sulfur-containing additives could react with Fe to produce Fe Sx and "M—C" bonds("M" represents metal). They both had contributions to the lubrication. As for the phosphorus-containing additives, they only generated the phosphates during the tests. When the sulfur and phosphorus-containing additives were applied, the generated phosphates and Fe Sx had the primary contribution to the lubrication performance during the tests.     

硼氮化改性菜籽油润滑添加剂对钢-钢摩擦副和钢-镁摩擦夫摩擦学性能的影响

A BN-containing additive,the boron and nitrogen modified rapeseed oil (abbreviated as BNR),was prepared by chemical modification of rapeseed oil with boric and nitrous compounds.The friction and wear performances of the AZ91D magnesium alloy against the GCr15 bearing steel under lubrication of rapeseed oil containing BNR were evaluated on a SRV tribotester.The topography and chemical species of the worn surfaces of magnesium alloy were analyzed by a scanning electron microscope (SEM) and an X-ray photoelectron spectroscope (XPS),respectively.The test results indicated that the friction and wear of the magnesium alloy-steel tribomates could be effectively reduced by incorporating BNR into the rapeseed oil lubricant.The friction coefficients and the wear scars of magnesium alloy decreased with an increasing content of BNR.The surface lubricated with the BNR-doped rapeseed oil demonstrated less wear as compared with that lubricated with neat rapeseed oil.The enhanced anti-wear and friction-reducing abilities of rapeseed oil provided by BNR in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of BNR and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.     

Preparation and Tribological Behavior of Hydrophobic Lanthanum Borate Nanosheets in Rapeseed Oil

Oleic acid-capped lanthanum borate(abbreviated as OA/La BO_3·H_2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/La BO_3·H_2O were characterized by means of SEM, TEM, EDS, FTIR and XRD, respectively. Moreover, the friction and wear properties of OA/La BO_3·H_2O as a lubricant additive in rapeseed oil were evaluated on a four-ball tribotester. The tribochemical characteristics of worn surfaces were investigated by SEM and XPS. The results showed that the hydrophobic OA/La BO_3·H_2O nanosheets exhibited their morphology with a diameter in the range of 100 nm to 300 nm and a thickness of about 25 nm, and displayed excellent dispersing stability in rapeseed oil. In the meantime, the rapeseed oil doped with OA/La BO_3·H_2O nanosheets markedly decreased the friction and wear of steel balls, and the optimal friction-reducing and antiwear ability of rapeseed oil was obtained at an OA/La BO_3·H_2O content of 1.0%. The outstanding tribological performance of OA/La BO_3·H_2O in rapeseed oil was attributed to the formation of a composite boundary lubrication film mainly composed of lubricious tribochemical species of B_2O_3, La_2O_3 and Fe_2O_3, and deposits of OA/La BO_3·H_2O nanosheets as well as the adsorbates of rapeseed oil on rubbed surfaces.     

不锈钢冷轧薄板轧制油研制

不锈钢、钛、钛合金、镍基合金是钢中较特殊的,镍、钴含量高,它们硬且低热传导性,使得在碎屑中形成高温,轧辊与碎屑交互面的温度也很高,使轧辊产生磨损和轧板划痕及变形,通过对油性轧制油的配方组分性能评定和配方设计,结合不锈钢冷轧设备的原理工艺特点,研制出性能较好的不锈钢冷轧薄板轧制油。     

不锈钢板冷轧润滑剂

介绍了不锈钢冷轧加工的性能及对润滑剂的要求,润滑剂对不锈钢板的冷轧加工有较大的影响,要根据实际情况选择合适的润滑剂.     

加氢油在金属轧制油中的应用研究

利用加氢油研制出铝材、铜材及不锈钢轧制油。应用结果表明,加氢油是生产金属轧制油的理想基础油。     

不锈钢薄板色差产生原因与消除方法探讨

介绍了不锈钢薄板轧制过程中轧制工艺参数和轧制油对板面质量的影响,分析了西南某不锈钢厂偏8辊轧机生产过程中板面出现色差的原因及解决办法,对比了两种轧制油的使用效果。新开发的轧制油轧制不锈钢薄板时不会出现色差等表面质量缺陷,而且轧制的带钢更薄,提高了生产效率,降低了生产成本。     

不锈钢轧制过程板面缺陷分析及对策

介绍了不锈钢薄板轧制过程中设备状态及轧制油对板面质量可能产生的影响及相应的解决办法。分析了东北某精密不锈钢公司轧制过程中板面产生缺陷的主要原因,提出相应的改进措施。指出合理的轧制工艺、良好的设备状态、性能优异的轧制油相互配合才能生产出高质量的产品。当板面质量出现问题时,应当从轧制工艺、设备状态、轧制油几个方面进行分析,找出主要矛盾对症下药,才能制定出合理的改进措施。     

钢板冷轧乳化油的研究

通过对基础油和添加刺的考察，得到了钢板冷轧乳化油的配方。实际使用结果表明，研制配方具有良好的润滑性和冷却性，完全满足钢板冷轧工艺的润滑和冷却要求。     

冷轧油性能对薄板高速冷轧机轧后钢板表面热划伤的影响

钢带冷连轧机高速轧制,尤其是轧制极薄料时轧后钢板表面以及轧制工作辊表面容易出现热划伤。严重热划伤时需要立即更换工作辊,并且钢卷会被降级处理。宝钢某冷连轧机组是台西马克5机架6辊连轧机组,在轧制0.5 mm以下的薄料时轧制速度超过800 m/m in容易出现热划伤,因此薄料轧制速度需要控制在此速度以下,极大地影响了轧机产量。文章对该冷轧机组的划伤现象进行了分析,通过优化冷轧油配方,加强辊缝润滑和冷却解决了热划伤问题。研究结果表明:冷轧油在高温高压条件下辊缝中成膜性能、润滑性能以及冷轧油乳化液对辊缝的冷却性能等都是热划伤产生的影响因素。对轧制油这些性能进行针对性优化,是提高薄料轧制速度和改善热划伤的有效手段。     

钢轧制润滑油概述

概要介绍了钢热轧润滑油的组成及其润滑特性、钢热轧的影响因素。还介绍了钢冷轧中出现的热擦痕和污渍的产生机理以及提高耐热擦痕性和清净性的措施。