In this research, the four-ball tribometer was examined to evaluate the tribological behavior of environment-friendly nano-MoS2 water-based rolling liquid. This experimental method is used to measure the maximum non-seizure load (PB) and the coefficient of friction (μ). The newly introduced parameter ω can be combined with PB and μ to evaluate the tribological performances of the rolling liquid comprehensively. The rolling lubrication performance of nano-MoS2 water-base lubricant was investigated using a single stand 4-high reversing rolling mill. The surface morphologies and rolling textures of the samples were measured by laser scanning confocal microscope after cold rolling. The results show that when the concentration of nano-MoS2 is 0.4wt.%, the water-based rolling liquid has excellent tribological and lubricating properties. Meanwhile, compared with the surface quality of the rolled strip under other lubrication conditions, the surface quality of the cold-rolled strip using 0.4wt% nano-MoS2 rolling liquid as the lubrication condition is smooth without visible surface defects.

The abrasive particles in the working emulsion were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The wettability and lubricating properties of different emulsion samples were tested by MRS-10E four-ball friction and wear testing machine. The results show that the average particle size of the abrasive particles in the working emulsion is 2.72 μm, the smallest particle size of the abrasive particles is 0.36μm, and the largest size of the abrasive particles is 6.57μm. Furthermore, the abrasive particles can increase the internal friction of emulsions, which leads to the increasing wetting Angle. The abrasive particles cause the lubrication performance of working emulsion to decrease, which eventually leads to larger wear scar diameter and the worse morphology of wear scar on the tested ball.