Abstract:The fretting wear of 2507 super duplex stainless steel under various amplitude was studied in the air and aqueous solutions using the SRV-IV wear testing machine.The 3D optical microscope and scanning electron microscope were used to analyze the worn depth,worn volume and worn surface morphology.Results show that under the condition of dry friction,the fretting regime is gradually transformed from partial slip to gross slip,and the friction coefficient is increased first and then becomes stable with the increasing of fretting amplitude,and the wear depth is increased with the increasing of fretting amplitude.The wear mechanism is transformed from the mild oxidation and local fatigue damage to the combination damage of oxidation,adhesion and delamination wear under the condition of dry friction.In aqueous solutions medium,the fluctuation of friction coefficient with the fretting amplitude in seawater is larger than that in deionized water,due to the synergistic effect of corrosion and wear in seawater,the worn depth and worn volume are also slight larger than those in deionized water.The mild oxidation wear,abrasive wear with fatigue wear are dominated under aqueous solutions.