Precipitation Characterization and Mechanical Behavior in Novel DP Steels
Dual precipitates of carbide and copper particles formed within Cu-Ti microalloyed DP (Dual Phase) steel in the present study. The precipitation behaviors of tiny precipitates, especially in the ferrite matrix, were checked precisely by several methods, such as optical microscopy, high resolution transmission electron microscopy, and hardness testing. It was found that copper particles nucleated only on the interphase precipitated TiC and were not dispersed randomly within the ferrite matrix. Therefore, the formation of dual precipitates within the ferrite grains should be considered as separated phase transformation; initially, only titanium carbides form during the austenite decomposition reaction, after which copper particles heterogeneously nucleate on these carbides. Furthermore, as compared to Cu microalloyed DP steel, the tempering behavior of martensite in the Cu-Ti microalloyed DP steel showed a tempering hardening characteristic.
Umemura Kazuo, Harald Justnes, Ki-Bum Kim and Takashiro Akitsu
C. Y. Chen et al., "Precipitation Characterization and Mechanical Behavior in Novel DP Steels", Materials Science Forum, Vol. 939, pp. 9-15, 2018