Research on Shear Bearing Capacity of High-Strength Bolted Connections of Weathering Steel Based on Crevice Corrosion

The connection structure of metal materials faces serious corrosion failure during long-term service, and the crevice corrosion has a significant impact on the shear bearing capacity of the connection structure. 6 high-strength bolted connectors composed of Q355GNH weathering steel and 6 high-strength bolted connectors composed of Q355B low-carbon steel were tested for accelerated corrosion in acetic acid salt spray. The corroded connectors with the rust outside the gap were used as the control group, and the rust outside the gap of the connecting plate was continuously cleaned during the corrosion process to study the crevice corrosion behavior, as well as the influence of crevice corrosion on the shear bearing capacity of the bolted connectors. The results showed that the anti-slip coefficient μ of the friction surface of the connector increased accordingly with the increase of the proportion of black rust. The rust produced by the weathering steel were dense, which could prevent oxygen to promote the low-oxygen crevice corrosion reaction, after removing the rust outside the gap, the black rust on the friction surface were reduced and the slip load was reduced by 29.2%. Whether the outer rust of the gap was removed or not, the crevice corrosion degree of the low-carbon steel bolted connectors was large, but the low-carbon steel connection that cleaned the outer rust of the gap had greater slip load through changing the roughness of friction surface of bolted connectors, crevice corrosion slowed down the decrease of anti-slip bearing capacity of bolted connectors caused by preload loss.