Assessment of Hydrogen Assisted Degradation of Stacker Conveyor Boom Steel

Abstract

An experimental investigation of operational degradation of the low carbon steel long-term operated under combined cyclic loading and environmental actions was carried out. The steel in different states, after 30-year operation under tensile and compressive cyclic loading and unloading one, the reference steel, was studied. The degradation degree of the post-operated steel was evaluated by mechanical, electrochemical and corrosion fatigue testing. A significant decrease in impact toughness, plasticity and corrosion resistance of the operated steel, compared to these characteristics of the reference steel, was revealed. The residual hydrogen concentration in the operated steel was significantly higher than in the reference steel. The environmental acceleration effect on crack growth rate was not revealed for the reference steel. However, fatigue crack growth rate in the operated metal was accelerated in the environment simulating acid rainwater in industrial region.