Effect of Content of Graphene on Corrosion Behavior of Micro-Arc Oxidation Coating on Titanium Alloy Drill Pipe

To improve the corrosion resistance of titanium alloy drill pipe, graphene particles was added into the electrolyte and micro-arc oxidation composite coating was formed with different graphene contents on the surface of TC4 titanium alloy. The corrosion characteristics of titanium alloy micro-arc oxidation film were analyzed by electrochemical workstation. The galvanic corrosion performance between TC4 titanium alloy and S135 steel was measured by galvanic corrosion tester. Results showed that on the surface of TC4 titanium alloy after micro-arc oxidation treatment, there is a dense oxide coating with good stability and high electrical resistance, which can effectively stabilize and reduce the galvanic current, so the coupling of micro-arc oxidation coating and S135 steel after galvanic pairing the current is significantly reduced. Micro-arc oxidation treatment of titanium alloy can improve surface corrosion resistance and reduce galvanic corrosion sensitivity. It is also found that the optimum graphene addition is 3 g/L under the experimental conditions.