Abstract:In order to study the corrosion resistance of the SAF2507 duplex stainless steel (SAF2507 DSS) propeller blades in seawater containing sulfate-reducing bacteria (SRB) and iron oxidizing bacteria (IOB), a secondary quench stamping technology was proposed to stamping SAF2507 DSS propeller blades.The corrosion behavior of propeller blades in seawater containing SRB and IOB was studied according to the precipitated phases types and precipitation laws of the propeller blades at different secondary quench stamping temperatures.The results showed that when the secondary quench stamping temperature was 700℃,a small amount of χ phases was precipitated on the surface of the propeller blades;and when it reached 850℃, the χ phases is completely converted to the σ phases, and the precipitation of σ phases reach the peak value,and at 950 ° C only a small number of σ phases are precipitated.The variation laws of the corrosion current density,Ac impedance and other electrochemical properties of propeller blades at different secondary quench stamping temperatures was consistent with that of χ phases and σ phases in the surface layer of propeller blades and the corrosion resistance characteristics of χ phases and σ phases themselves.When the secondary quench stamping temperature was between 750 ° C and 1050 ° C, the corrosion resistance of propeller blades changes in the rule of "enhancement - reduction - enhancement" with the increase of the secondary quench stamping temperature, and the corrosion resistance of propeller blades was the worst at 850 ° C in seawater containing SRB and IOB.For the surface characteristics of the rich Fe on the surface layer of propeller blade after secondary quench stamping, the surface passivation film of propeller blade was damaged in seawater containing SRB and IO, which leads to the decrease of corrosion resistance.