Experimental study on corrosion behavior and failure mechanism of bolts in acidic environment

To investigate the corrosion resistance and failure process of various metal bolts within acidic environment. The comparative corrosion experiment was conducted on ordinary, zinc-immersed, and zinc-infiltrated bolts. The corrosion behavior and mechanism were analyzed in these three types of bolts. The results showed that within an acidic milieu, the corrosion resistance of ordinary bolt is notably inferior, succeeded by zinc-immersed bolts, and the zenith of corrosion resistance is observed in zinc-infiltrated bolts. The instantaneous corrosion rate constants for these bolts are found to be 0.25026, −0.19605, and −0.06209, respectively. After 100 days of corrosion, the degradation in mechanical properties for the three bolts manifested as the yield strength decreased by 6.50 %, 4.63 %, and 2.85 %, respectively, and the tensile strength decreased by 6.37 %, 3.99 %, and 1.45 %, respectively, and the elongation decreased by 15.85 %, 12.20 %, and 7.97 %, respectively. As the corrosion advanced, the tensile fracture behavior of ordinary bolt transitions from ductile fracture to ductile-brittle hybrid fracture, the tensile fracture behavior of zinc-immersed and zinc-infiltrated bolts remains ductile fracture. The corrosion process for the ordinary bolt follows dissolution-destruction mechanism, the zinc-immersed bolt follows dissolution-destruction-penetration mechanism, and the zinc-infiltrated bolt follows dissolution-transformation mechanism.