Failure Reason Analysis of Babbitt Alloy on the Surface of Bearing Bush

Abstract

For various heavy - load, high - speed and low - speed plain bearings, burning and failure of Babbitt alloy due to the instability of the lubricating oil film is very common. Through the surface oil film analysis, surface crack morphology observation, chemical composition inspection, cross - section metallographic structure inspection and energy dispersive spectrum analysis of the failed Babbitt alloy on the surface of a bearing bush, it was found that the carbon deposition on the surface of Babbitt alloy caused uneven stress distribution on it. And plastic flow occurred on the surface of Babbitt alloy under the action of friction, forming macroscopic friction marks. And the cracking occurred in the repair welding area of Babbitt alloy with low hardness and welding defects, and propagated along the direction of layer depth. In addition, the acidic solution formed due to the high content of Na+ and water in the oil film on the surface of Babbitt alloy led to an electrochemical corrosion of Babbitt alloy which then resulted in corrosion pits.

Keywords

• babbitt alloy|failure; hard phase β|electrochemical corrosion|electrochemical corrosion pits