阅读说明：本技术 一种铁路轮轨润滑脂及其制备方法 (Railway wheel-rail lubricating grease and preparation method thereof ) 是由 杨操 张勇 朱国靖 于 2019-08-08 设计创作，主要内容包括：本发明公开了一种铁路轮轨润滑脂及其制备方法,润滑脂按重量百分比计包括以下组分：基础油40％～50％、高碱值合成磺酸钙30％～35％、转化剂4％～5％、膨润土稠化剂3％～5％、助分散剂0.3％～0.5％、抗氧剂1.0％～1.5％、防锈剂0.1％～0.5％和极压抗磨剂10％～15％,高碱值合成磺酸钙的碱值为350～450KOH/g,碳酸钙的粒度≤10μm。该润滑脂具有优异的耐高低温性、极压抗磨性、胶体安定性、泵送性、防锈性及生物降解性；选择高碱值合成磺酸钙制备磺酸钙基脂,能够有效提高润滑脂的低温流动性和黏附性,还能显著提高铁路轮轨的抗磨损能力,延长设备使用寿命；该制备方法的生产工艺简单。(The invention discloses a railway wheel-rail lubricating grease and a preparation method thereof, wherein the lubricating grease comprises the following components in percentage by weight: 40-50% of base oil, 30-35% of high-base-number synthetic calcium sulfonate, 4-5% of transforming agent, 3-5% of bentonite thickening agent, 0.3-0.5% of auxiliary dispersant, 1.0-1.5% of antioxidant, 0.1-0.5% of antirust agent and 10-15% of extreme pressure antiwear agent, wherein the base number of the high-base-number synthetic calcium sulfonate is 350-450 KOH/g, and the particle size of calcium carbonate is less than or equal to 10 mu m. The lubricating grease has excellent high and low temperature resistance, extreme pressure abrasion resistance, colloid stability, pumpability, rust resistance and biodegradability; the calcium sulfonate base grease prepared by synthesizing the calcium sulfonate with a high base number can effectively improve the low-temperature fluidity and the adhesiveness of the lubricating grease, obviously improve the abrasion resistance of the railway wheel rail and prolong the service life of equipment; the preparation method has simple production process.)

1. The railway wheel-rail lubricating grease is characterized by comprising the following components in percentage by weight: 40 to 50 percent of base oil, 30 to 35 percent of high-base-number synthetic calcium sulfonate, 4 to 5 percent of transforming agent, 3 to 5 percent of bentonite thickening agent, 0.3 to 0.5 percent of auxiliary dispersant, 1.0 to 1.5 percent of antioxidant, 0.1 to 0.5 percent of antirust agent and 10 to 15 percent of extreme pressure antiwear agent; the base number of the high-base-number synthetic calcium sulfonate is 350-450 KOH/g, and the particle size of the calcium carbonate serving as an effective component is less than or equal to 10 mu m.

2. The railway wheel track grease of claim 1 wherein the base oil comprises at least one of a mineral oil, a polyalphaolefin oil, or an ester oil, the ester oil being one of pentaerythritol ester, trimethylolpropane ester, or dioctyl sebacate.

3. The railway wheel-rail grease of claim 1 or 2, wherein the base oil has a kinematic viscosity of 10 to 50mm at 40 ℃²And/s, pour point not higher than-45 ℃.

4. The railway wheel grease of claim 1 wherein the conversion agent is a mixture of water, an alcohol and an acid, the alcohol is isopropanol and the acid is dodecylbenzene sulfonic acid.

5. The railway wheel track grease of claim 1 wherein the bentonite thickener is an organobentonite.

6. The railway wheel grease of claim 1 wherein the dispersion aid is propylene carbonate.

7. The railway wheel track grease of claim 1, wherein: the antioxidant is 2, 6-dibutyl-p-cresol and/or alkyl diphenylamine.

8. The railway wheel track grease of claim 1, wherein: the antirust agent is benzotriazole and/or sodium benzotriazole.

9. The railway wheel track grease of claim 1, wherein: the extreme pressure antiwear agent is a mixture composed of zinc oxide, light calcium carbonate and graphite fluoride, and the particle size of the extreme pressure antiwear agent is less than or equal to 5 mu m.

10. A method of preparing the railway wheel track grease of claim 1, comprising the steps of:

(1) mixing the high-base-number synthetic calcium sulfonate with part of base oil according to the weight percentage, uniformly stirring, adding a conversion agent, heating to 70-80 ℃, and keeping the temperature for 2-2.5 hours, wherein the mass ratio of the base oil to the high-base-number synthetic calcium sulfonate is 1: 1-1: 2;

(2) continuously heating to 120-140 ℃, then preserving heat for 0.5-1 h, adding the rest base oil, and cooling to room temperature;

(3) adding a bentonite thickening agent, stirring uniformly, adding a dispersion aid, stirring for 0.5-1 h, after homogenizing, sequentially adding an antioxidant, an antirust agent and an extreme pressure antiwear agent, stirring uniformly and degassing.

Technical Field

The invention relates to lubricating grease and a preparation method thereof, in particular to railway wheel-rail lubricating grease and a preparation method thereof.

Background

With the development of global economy, the power of railway transportation is changed obviously. The transportation load of the internal combustion engine and the electric locomotive exceeds the transportation load of the steam locomotive, and a great step is taken towards the aspects of heavy load, extension and high speed. The improvement of the application conditions leads the locomotive wheel rim and the steel rail (especially the curved steel rail) to be worn, which is a long-existing harmful disease on the railway, to be more and more prominent, and directly influences the service life of the wheel and the rail and the transportation production safety.

During the running process of the railway locomotive, the wheel rim is contacted with the inner side surface of the steel rail due to the fact that the train inclines in the running process, and therefore frequent friction is generated. Particularly, when the locomotive runs on a curve road section, the wheels are extruded to the steel rail due to the centrifugal force, so that the inner side surface of the steel rail is severely rubbed with the wheel rim of the wheels to be seriously abraded, and the service lives of the steel rail and the wheels are shortened. Lubricating the inside of the rail and the edge of the wheel with a lubricant is one of the most effective methods for reducing the friction between the wheel rim and the rail, reducing the power loss of the locomotive, improving the interaction between the wheel and the rail, and reducing the friction between the wheel and the rail.

Therefore, aiming at the working characteristics of the railway wheel rail, the high performance requirement is provided for the wheel rail lubricating grease: (1) high temperature resistance: when the train runs on a downhill, the temperature of the wheels can be raised to 200 ℃ by the friction heat between the wheels and the steel rails, the train runs on a small-diameter curve section, and the temperature of the wheel rails can also reach more than 150 ℃ when the maximum braking force is applied; (2) excellent viscosity-temperature characteristics: the device is suitable for temperature changes in winter and summer in the north and south of China, has no obvious phenomenon of thinning or thickening, keeps excellent pumping performance and jetting capacity, and is used in all weather; (3) excellent extreme pressure antiwear properties: the surface of the wheel-rail friction pair can only form boundary lubrication, and the wheel-rail friction pair has excellent extreme pressure antifriction performance to meet the working conditions of large load and high sliding speed of a contact surface between a wheel rim and a rail side; (4) excellent adhesion and adhesion: the wheel has enough adhesive force and adhesiveness to overcome the centrifugal force generated in the running process of the wheel, is not thrown off, and simultaneously expands into a uniform oil film in a spraying area in time; (5) excellent water resistance: the lubricating grease is ensured not to be washed and emulsified by water in use, and the normal use in rainy and snowy weather is ensured; (6) excellent dust-proof and corrosion-proof properties; (7) the grease sprayer has better matching performance with a grease sprayer, and can be matched with a wheel rail lubricating grease spraying system loaded on a locomotive for use.

And the lubricating grease used on the railway wheel rail is a disposable consumption material, is sprayed on the wheel rim and the steel rail and directly escapes to the environment, thus easily causing environmental pollution. With the development of modern railways and increasingly severe environmental requirements, the wheel-rail lubricating grease is required to have the characteristics of small environmental pollution and biodegradability. Patent No. CN104450106A discloses a preparation method of a wheel rail dedicated grease and CN106833819A discloses a preparation method of a wheel rail antifriction grease, both lithium hydroxystearate soap is used as a thickener, and solid additives and polymers are added to improve extreme pressure property and water resistance of the grease, so that environmental protection is not considered, and the grease is not easily biodegradable; patent No. CN105950267A discloses a preparation method of environment-friendly wheel-rail lubricating grease, which is characterized in that fatty acid lithium soap or calcium soap is adopted to thicken synthetic base oil, and sulfur, phosphorus, boron or nitrogen-containing anti-wear agents and white solid additives are added to improve the extreme pressure anti-wear performance of the lubricating grease, and patent No. CN105907448A discloses a preparation method of lubricating grease for a railway locomotive wheel rim, wherein low pour point composite sulfonate thickened synthetic oil is adopted, and the lubricating grease has low thickening agent content to improve low temperature fluidity and excellent extreme pressure anti-wear performance and water-resistant anti-rust performance, but the preparation process is relatively complex.

Disclosure of Invention

The purpose of the invention is as follows: in view of the above problems, a first object of the present invention is to provide an environmentally friendly grease having excellent high and low temperature resistance, extreme pressure wear resistance, colloid stability, pumpability, rust resistance and biodegradability. The second purpose of the invention is to provide a preparation method of the lubricating grease.

The technical scheme is as follows: the railway wheel track lubricating grease comprises the following components in percentage by weight: 40 to 50 percent of base oil, 30 to 35 percent of high-base-number synthetic calcium sulfonate, 4 to 5 percent of transforming agent, 3 to 5 percent of bentonite thickening agent, 0.3 to 0.5 percent of auxiliary dispersant, 1.0 to 1.5 percent of antioxidant, 0.1 to 0.5 percent of antirust agent and 10 to 15 percent of extreme pressure antiwear agent.

Preferably, the base number of the high-base-number synthetic calcium sulfonate is 350-450 KOH/g, and the particle size of the calcium carbonate contained in the high-base-number synthetic calcium sulfonate is less than or equal to 10 mu m. The conversion agent is a mixture of water, alcohol and acid, wherein the alcohol is isopropanol, and the acid is dodecylbenzene sulfonic acid. The calcium sulfonate base grease prepared from the raw materials can effectively improve the low-temperature performance of the lubricating grease; in the traditional process, the calcium sulfonate used in the traditional process has the defects that the low-temperature performance of the calcium sulfonate-based lubricating grease is poor due to the fact that the particle size of the calcium carbonate serving as an effective component in the calcium sulfonate is too large (the particle size is 60 mu m or even more than 100 mu m), aggregation is easy to occur, and particularly, the hardening phenomenon is serious due to the addition of the composite component, so that the calcium sulfonate-based lubricating grease is not suitable for being used at.

The base oil comprises at least one of mineral oil, poly-alpha-olefin oil or ester oil, the ester oil is one of pentaerythritol ester, trimethylolpropane ester or dioctyl sebacate, and the kinematic viscosity of the base oil at 40 ℃ is 10-50 mm²And/s, pour point not higher than-45 ℃. The viscosity adopted by the invention is 10-50 mm²The base oil is more suitable for being used in a grease sprayer of a locomotive-mounted wheel rail system, if the viscosity is too low, a sufficient oil film cannot be formed, and if the viscosity is too high, the fogging property is poor.

According to the invention, the organic bentonite thickener is added into the calcium sulfonate-based lubricating grease, and the propylene carbonate is selected as the auxiliary dispersant, so that the pumpability and the colloidal stability of the lubricating grease can be well improved, the service life of the lubricating grease is prolonged, and the grease replacement period is prolonged.

The antioxidant is 2, 6-dibutyl-p-cresol and/or alkyl diphenylamine. The antirust agent is benzotriazole and/or sodium benzotriazole. The extreme pressure antiwear agent is a mixture consisting of zinc oxide, light calcium carbonate and graphite fluoride, preferably, the particle size of the extreme pressure antiwear agent is less than or equal to 5 mu m, and the solid additive can effectively reduce rail abrasion, has small pollution to the environment and meets the requirement of environmental protection.

By adopting the antioxidant, the antirust agent and the extreme pressure antiwear agent and reasonably compounding the additives, the invention ensures that the PD value of the lubricating grease reaches 4904N, the diameter of the wear scar is less than 0.4mm, the extreme pressure antiwear property is excellent, and the continuous lubrication of equipment can be effectively ensured.

The method for preparing the lubricating grease comprises the following steps:

(1) mixing the high-base-number synthetic calcium sulfonate with part of base oil according to the weight percentage, uniformly stirring, adding a conversion agent, heating to 70-80 ℃, and keeping the temperature for 2-2.5 hours, wherein the mass ratio of the base oil to the high-base-number synthetic calcium sulfonate is 1: 1-1: 2;

(2) continuously heating to 120-140 ℃, then preserving heat for 0.5-1 h, adding the rest base oil, and cooling to room temperature;

(3) adding a bentonite thickening agent, stirring uniformly, adding a dispersion aid, stirring for 0.5-1 h, after homogenizing, sequentially adding an antioxidant, an antirust agent and an extreme pressure antiwear agent, stirring uniformly and degassing.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: (1) the lubricating grease has excellent high and low temperature resistance, extreme pressure wear resistance, colloid stability, pumpability, rust resistance and biodegradability, and belongs to environment-friendly lubricating grease; (2) the calcium sulfonate base grease is prepared by synthesizing calcium sulfonate with a high base number of 350-450 KOH/g and calcium carbonate with the granularity of less than or equal to 10 mu m, so that the low-temperature fluidity and the adhesiveness of the lubricating grease can be effectively improved, the effective component of the calcium sulfonate with the high base number is higher, the abrasion resistance of the railway wheel rail can be obviously improved, and the service life of equipment is prolonged; (3) the preparation method has the advantages of maximum refining temperature of 140 ℃, simple production process and short production time.

Detailed Description

The present invention will be further described with reference to the following examples.