Industrial Gear Oil is widely used in steel, cement, coal, petrochemical and many other industries. With the rapid development of the national economy, its consumption is increasing year by year. In 2020, the domestic demand has reached 310000 t/a. According to the requirements of GB5903-2011, 16 physical and chemical indexes and bench performance of industrial gear oil, including kinematic viscosity, liquid phase corrosion, oxidation stability, four ball extreme pressure and anti-wear, and FZG bearing capacity, shall be tested before delivery. Some of the test items have a long period (for example, oxidation takes 13d) and high cost (FZG is 20000 yuan/time), which results in many oil batch test items, high test cost and delayed delivery, which is not conducive to timely supply to customers. If the factory batch inspection items are reasonably simplified according to the industrial gear oil formula and product performance characteristics, it can effectively avoid repeated waste and help the market to ensure supply. Characteristics of gear oil formula Industrial gear oil is developed according to the characteristics of gear box working conditions. It is generally required to have appropriate viscosity, good viscosity temperature performance, sufficient extreme pressure and anti-wear performance, good oxidation stability, anti emulsification performance, Anti Foam performance, rust prevention and corrosion resistance, etc., mainly involving extreme pressure agent, anti-wear agent, Friction Improver, Pour Point Depressant, antioxidant, rust inhibitor, copper Corrosion Inhibitor, demulsifier, anti foam agent and other additives. According to the main role of additives in lubricating oil, according to the functional classification, that is, "substances are divided into three groups according to their functions": (1) Tribo improvers, including friction improvers, antiwear agents, extreme pressure additives, etc., play a central role in the lubricant formula and directly contribute to improving the tribological properties of lubricants; (2) Rheology - improving additives, including viscosity improvers and pour point depressants, mainly improve the lubrication performance by changing the volume characteristics of liquid under hydrodynamic conditions, mainly involving the fluidity of Base Oil; (3) Maintainers refer to additives that help to keep substances (lubricants and materials of mechanical components) in good condition by preventing the deterioration of substances in the lubrication system. Their main role is to help extend the life of the lubrication system and, in some cases, to improve the lubrication performance. Such as antioxidants, corrosion inhibitors (including rust inhibitors), anti foaming agents and demulsifiers. In addition to the classification according to the function of additives, they can also be classified by their action points and action mechanisms. For example, they can be classified into interface agents and dispersants according to the action points, and chemical additives and physical additives according to the action mechanisms. Extreme pressure agent, antiwear agent, friction improver, antioxidant and corrosion inhibitor are all chemical action mechanisms, and they have mutual influence, such as competitive adsorption. Physical additives include pour point depressants, demulsifiers and antifoam agents. According to the chemical action, physical action and interface action mechanism of additives. The most important extreme pressure performance of industrial gear oil is closely related to the extreme pressure antiwear agent, antirust agent and base oil in the formula; If the type and dosage of additives are identical, increasing the viscosity level of gear oil can increase the oil film thickness and enhance the oil bearing capacity; Namely, under the same additive, the same base oil group has the same classification but different proportions of the same source base oil formula, and the high viscosity industrial gear oil carries higher loads than the low viscosity industrial gear oil. Therefore, for the industrial gear oil formula with the same additives and the same source of base oil, the bearing performance of low viscosity grade oil can be read up to the same source high viscosity grade. The oxidation performance has a strong correlation with the antioxidant, extreme pressure agent and base oil in the formula. According to experience, the oxidation resistance of similar low viscosity base oils is better than that of high viscosity base oils. Therefore, the oxidation resistance of high viscosity gear oils can be read down to the same low viscosity level. The low temperature performance of homologous low viscosity base oil is better than that of homologous high viscosity base oil, so the pour point situation is similar, that is, when the pour point depressant and dosage are the same, the pour point of the formula with high viscosity level can be read down to the homologous low viscosity level.
