The sub-rapid solidification(SRS)process associated with twin-roll strip casting(TRSC)is characterized by weakened elemental segregation and selective crystal growth,offering significant advantages compared with conve...The sub-rapid solidification(SRS)process associated with twin-roll strip casting(TRSC)is characterized by weakened elemental segregation and selective crystal growth,offering significant advantages compared with conventional casting methods.The interrelationship of the cooling rate,microstructure/texture evolution,and segregation behavior along the thickness direction of as-cast 18Ni–Mo–Co maraging steel strip produced by TRSC was investigated.The results revealed that the solidification microstructure of as-cast maraging steel strip exhibits the directional dendrite growth with preferred{001}texture under SRS condition.It was also found that the synchronous enrichment of Ni,Mo,and Ti elements appears in the as-cast strip to form microsegregation bands.The solidification path of the designed maraging steel strip involves the phase transformation from liquid→γ→α.Additionally,the presence of microsegregation bands of Ni and Mo allows a portion of the austenite(6–9 vol.%)to remain at room temperature after undergoing solid-state phase transformation.It could be observed that the microstructure of as-cast 18Ni–Mo–Co maraging steel strip consists of martensite and austenite,with the austenite distributed alternatively at the interdendritic positions.Ultimately,the interrelationship among solidification cooling rate,element segregation,and solidification microstructure evolution during the SRS process of 18Ni–Mo–Co maraging steel was clarified.展开更多
基金supported by National Key Research and Development Program of China(Nos.2023YFB3710203 and 2023YFB3710202)National Natural Science Foundation of China(Nos.52304361 and 52130408)Natural Science Foundation of Hunan Province(No.2023JJ40737).
文摘The sub-rapid solidification(SRS)process associated with twin-roll strip casting(TRSC)is characterized by weakened elemental segregation and selective crystal growth,offering significant advantages compared with conventional casting methods.The interrelationship of the cooling rate,microstructure/texture evolution,and segregation behavior along the thickness direction of as-cast 18Ni–Mo–Co maraging steel strip produced by TRSC was investigated.The results revealed that the solidification microstructure of as-cast maraging steel strip exhibits the directional dendrite growth with preferred{001}texture under SRS condition.It was also found that the synchronous enrichment of Ni,Mo,and Ti elements appears in the as-cast strip to form microsegregation bands.The solidification path of the designed maraging steel strip involves the phase transformation from liquid→γ→α.Additionally,the presence of microsegregation bands of Ni and Mo allows a portion of the austenite(6–9 vol.%)to remain at room temperature after undergoing solid-state phase transformation.It could be observed that the microstructure of as-cast 18Ni–Mo–Co maraging steel strip consists of martensite and austenite,with the austenite distributed alternatively at the interdendritic positions.Ultimately,the interrelationship among solidification cooling rate,element segregation,and solidification microstructure evolution during the SRS process of 18Ni–Mo–Co maraging steel was clarified.
