Experimental study on corrosion of 3D printed bolts based on metal powder in simulated mine water

Due to groundwater erosion and the environmental impact of mining activities, bolts are prone to corrosion and even breakage. Investigating the corrosion resistance of bolts made from different materials using 3D printing technology is of significant importance for the application of 3D printing in mines. Employing electrochemical acceleration corrosion methods, this study examined the corrosion rate variations, phase composition, morphological structure, and tensile mechanical properties of 3D-printed bolts composed of three different metal powders—stainless steel (SS), die steel (DS), and aluminum alloy (AL)—in a simulated mine water environment, as well as traditional bolts(TB). The results indicate that before corrosion, the tensile strength and ductility of 3D-printed SS bolts are most similar to those of TB bolts. The corrosion rate and mass-specific corrosion rate of 3DDS bolts are higher at each stage compared to other bolts, while 3DSS bolts exhibit the lowest rates. Both 3D-printed and TB bolts experience varying degrees of corrosion on their surfaces. The surface of 3DSS bolts only exhibits local corrosion, whereas the original surface morphology of 3DDS, 3DAL, and TB bolts is substantially corroded, resulting in more severe corrosion. The corrosion products of TB, 3D SS, and 3DDS bolts are similar, mainly composed of phases such as Fe2O3, Fe3O4, and FeOOH, while the corrosion products of 3DAL bolts consist only of Al2O3 and Al(OH)3. The tensile strength and elongation at break of both 3D-printed and traditional bolts exhibit varying degrees of reduction after corrosion. Corrosion has a relatively minor impact on the tensile strength and elongation at the break of TB bolts, whereas 3DSS bolts experience the most significant reduction in tensile strength and ductility after corrosion. The research findings can provide theoretical references for the design and long-term stability evaluation of 3D-printed bolts in corrosive mining environments in the future.