The effect of solution annealing temperature ranging from 950 to 1 200 ℃ on the microstructure and corrosion performance of duplex stainless steel （DSS） 2204 were investigated. The proportion of the ferrite phase i...The effect of solution annealing temperature ranging from 950 to 1 200 ℃ on the microstructure and corrosion performance of duplex stainless steel （DSS） 2204 were investigated. The proportion of the ferrite phase increased while the austenite phase decreased and the ferrite stabilizing elements diluted in the ferrite phase with the increase of annealing temperature. The critical pitting temperature （CPT） of specimens annealed at 1000℃ was higher than those annealed at 950℃, whereas further increasing the annealing temperature to 1200℃ decreased the CPT. The pitting initiation sites were observed in the austenite phase, at the boundary of ferrite/austenite phase and inside the ferrite phase for specimens annealed at 950, 1000℃ and exceeding 1 100℃, respectively. The evolution trend of the CPT and the pit initiation site were analyzed by the pitting resistance equivalent number.展开更多
Carbon fiber reinforced plastics (CFRP) are promising lightweight materials for vehicle applications. 316L is one of the most widely used types of austenite stainless steels and applied in lots of automotive applicati...Carbon fiber reinforced plastics (CFRP) are promising lightweight materials for vehicle applications. 316L is one of the most widely used types of austenite stainless steels and applied in lots of automotive applications. The existence of crevices will result in galvanic corrosion and crevice corrosion when CFRPs and 316L are directly connected. A crevice former for the galvanic system was therefore designed and applied to evaluate the crevice corrosion behaviors and study the mechanism of galvanic crevice corrosion through several electrochemical techniques in this research. The results showed that the crevice corrosion of galvanic systems grew from crevice mouth to the inside crevice and could be divided into four steps, metastable pitting corrosion at the crevice mouth, initiating step of crevice corrosion, propagating step and ending step of crevice corrosion. Because of the influences of the galvanic system, electrode reaction rates were speeded up and the passivation region was shortened at the initiating stage of crevice corrosion. Corrosion rate was observed to be higher in the galvanic system than that in normal crevice systems.展开更多
基金Item Sponsored by National Natural Science Foundation of China(51131008,51371053)National Key Technology Research and Development Program of China(2012BAE04B00)Doctoral Fund of the Ministry of Education of China(20120071110013)
文摘The effect of solution annealing temperature ranging from 950 to 1 200 ℃ on the microstructure and corrosion performance of duplex stainless steel （DSS） 2204 were investigated. The proportion of the ferrite phase increased while the austenite phase decreased and the ferrite stabilizing elements diluted in the ferrite phase with the increase of annealing temperature. The critical pitting temperature （CPT） of specimens annealed at 1000℃ was higher than those annealed at 950℃, whereas further increasing the annealing temperature to 1200℃ decreased the CPT. The pitting initiation sites were observed in the austenite phase, at the boundary of ferrite/austenite phase and inside the ferrite phase for specimens annealed at 950, 1000℃ and exceeding 1 100℃, respectively. The evolution trend of the CPT and the pit initiation site were analyzed by the pitting resistance equivalent number.
基金supported by National Key Research and Development Program of China (Grants No. 2018YFB0704400)National Natural Science Fund of China (Grants Nos. 51671059, 51871061, 51801028)
文摘Carbon fiber reinforced plastics (CFRP) are promising lightweight materials for vehicle applications. 316L is one of the most widely used types of austenite stainless steels and applied in lots of automotive applications. The existence of crevices will result in galvanic corrosion and crevice corrosion when CFRPs and 316L are directly connected. A crevice former for the galvanic system was therefore designed and applied to evaluate the crevice corrosion behaviors and study the mechanism of galvanic crevice corrosion through several electrochemical techniques in this research. The results showed that the crevice corrosion of galvanic systems grew from crevice mouth to the inside crevice and could be divided into four steps, metastable pitting corrosion at the crevice mouth, initiating step of crevice corrosion, propagating step and ending step of crevice corrosion. Because of the influences of the galvanic system, electrode reaction rates were speeded up and the passivation region was shortened at the initiating stage of crevice corrosion. Corrosion rate was observed to be higher in the galvanic system than that in normal crevice systems.
