The transpassivation and pitting corrosion behavior of a high-nitrogen stainless steel(HNS),Fe18Cr15Mn3Mo0.92N,were systematically investigated by electrochemical analysis,morphology observation,and X-ray photoelectro...The transpassivation and pitting corrosion behavior of a high-nitrogen stainless steel(HNS),Fe18Cr15Mn3Mo0.92N,were systematically investigated by electrochemical analysis,morphology observation,and X-ray photoelectron spectroscopy surface analysis.It was surprisingly found that no pitting corrosion occurred in the transpassivation region of HNS.This electrochemical corrosion behavior is untypical for stainless steels,i.e.,the traditional critical pitting potential method was invalid for HNS.Both N and Cr enrichments in the transpassivation film on HNS were found extremely higher than those in the passivation film.The N existed in the form of[CrN]complex,which could stabilize the above both films.Besides,the corrosion product of N was detected as NH_(3) that exhibited an effective corrosion inhibition effect.On this basis,although the transition of Cr from 3-valent to 6-valent was confirmed,the transpassivation film on HNS still maintained it high stability and no pitting was found to occur.Therefore,the real pitting resistance of HNS should be higher than the expected before.And the stable transpassivation film played an important role in its untypical pitting corrosion resistance.展开更多
In this work,we demonstrate that the corrosion resistance of the FeCrNiCoNb_(0.5) eutectic high entropy alloy(EHEA)can be tuned by controlling the size of its eutectic structure.Through microstructure refinement,the E...In this work,we demonstrate that the corrosion resistance of the FeCrNiCoNb_(0.5) eutectic high entropy alloy(EHEA)can be tuned by controlling the size of its eutectic structure.Through microstructure refinement,the EHEA exhibits a superb corrosion resistance in 1 M NaCl in terms of a very low corrosion current density and an ultra-high transpassviation potential,which outperforms a variety of other HEAs and conventional metals and alloys.At the fundamental level,the microstructure refinement results in a rapid formation of a thick and compact passive film with less Cl-adsorption on the EHEA,which results in significant enhancement in its corrosion resistance.The outcome of our research provides important insights into the design of corrosion resistant chemically complex alloys.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.51801220).
文摘The transpassivation and pitting corrosion behavior of a high-nitrogen stainless steel(HNS),Fe18Cr15Mn3Mo0.92N,were systematically investigated by electrochemical analysis,morphology observation,and X-ray photoelectron spectroscopy surface analysis.It was surprisingly found that no pitting corrosion occurred in the transpassivation region of HNS.This electrochemical corrosion behavior is untypical for stainless steels,i.e.,the traditional critical pitting potential method was invalid for HNS.Both N and Cr enrichments in the transpassivation film on HNS were found extremely higher than those in the passivation film.The N existed in the form of[CrN]complex,which could stabilize the above both films.Besides,the corrosion product of N was detected as NH_(3) that exhibited an effective corrosion inhibition effect.On this basis,although the transition of Cr from 3-valent to 6-valent was confirmed,the transpassivation film on HNS still maintained it high stability and no pitting was found to occur.Therefore,the real pitting resistance of HNS should be higher than the expected before.And the stable transpassivation film played an important role in its untypical pitting corrosion resistance.
基金supported by the Research Grant Council(RGC),Hong Kong Government,through the General Research Fund(GRF)with the grant number City U11213118 and City U11209317。
文摘In this work,we demonstrate that the corrosion resistance of the FeCrNiCoNb_(0.5) eutectic high entropy alloy(EHEA)can be tuned by controlling the size of its eutectic structure.Through microstructure refinement,the EHEA exhibits a superb corrosion resistance in 1 M NaCl in terms of a very low corrosion current density and an ultra-high transpassviation potential,which outperforms a variety of other HEAs and conventional metals and alloys.At the fundamental level,the microstructure refinement results in a rapid formation of a thick and compact passive film with less Cl-adsorption on the EHEA,which results in significant enhancement in its corrosion resistance.The outcome of our research provides important insights into the design of corrosion resistant chemically complex alloys.
