Abstract: In order to meet the needs of the lean production of No.8 hydraulic transmission oil and achieve the prediction and control of the low temperature apparent viscosity of No.8 hydraulic transmission oil in the blending control room, the correlation between the physical properties and the low-temperature apparent viscosity of No.8 hydraulic transmission oil prepared from different raw materials was studied. In order to grasp the change rule of apparent viscosity at low temperature and establish a prediction model of apparent viscosity at low temperature,the correlation between density, viscosity index, kinematic viscosity and low-temperature apparent viscosity was further studied by using the response surface methodology and Design-expert 12.0 software. The results showed that the kinematic viscosity (A), viscosity index (B) and 20 ℃ density (C) of No.8 hydraulic transmission oil hada high correlation with low-temperature apparent viscosity. After fitting, the regression equation of apparent viscosity at low temperaturewas (Y)obtained: Y=2 032.74+123.28 A-1 142.98 B + 574.01 C+680.72 AB-1 294.84 AC-1 091.62 BC,which was verified by the application of No.8 hydraulic transmission oil produced by 8 batches of different raw materials, the predicted value of apparent viscosity at low temperature was basically consistent with the measured value, and the reliability of the regression equation model was high.

Key words: No.8 hydraulic transmission oil, low temperature apparent viscosity, viscosity index, density, kinematic viscosity, correlation