• Developed a set of electrolytic accelerated corrosion test device and testing method for anchor bolts • Revealed the dynamic evolution corrosion mechanism of anchor bolt rust layer in mine water environment • 3)Proposed the correlation between corrosion damage and mechanical performance degradation of anchor bolts • 4)Compared and evaluated the long-term protective performance differences of various anti-corrosion coatings Mine water environment significantly induces corrosion damage in bolt support systems, leading to premature failure long before their designed service life. To investigate this issue, this study conducted indoor accelerated corrosion tests using typical mine water from the Shendong mining area as the corrosive medium. The electrochemical corrosion behavior of bolts in mine water was analyzed, and the protective performance of commonly used anti-corrosion coatings was compared. The results show: (1) The corrosion process is governed by the dynamic evolution of the rust layer, with initial slow corrosion due to oxide protection, partial inhibition in the medium term, and sustained high rates later due to rust layer permeation. The cycle of rust layer "formation–destruction–reformation" induces local pitting and stress concentration, impairing bolt load capacity and durability. (2) Over time, the bolt surface transitions from smooth metal to loose oxides, with enlarged pits, accumulated corrosion products, and cracks, eventually forming multilayered coverings that accelerate corrosion. (3) Initially, an oxide film delays performance degradation; subsequently, subsurface corrosion reduces plasticity, and crack propagation leads to sharp declines in tensile strength and elongation. Micro-crack expansion and cross-section reduction jointly deteriorate ductility. (4) Chromium coating offers the best corrosion resistance, fluorocarbon coating performs well under stable conditions, and zinc coating suits mild environments but shows reduced long-term protection. Theoretically, this study reveals corrosion mechanisms in mine support systems, and the practical evaluation of coatings aids material selection for different mine water conditions, supporting extended system service life and roadway stability.
Liu et al. (Sun,) studied this question.