Experimental Determination of Continuous Cooling Transformation (CCT) Diagrams for Dual-Phase Steels from the Intercritical Temperature Range

Metals

Armando Salinas¹  Alfredo Flores¹  Krishna Bräutigam–Matus¹  Gerardo Altamirano²  Frank Goodwin³ 

[1] Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Saltillo, Av. Industria Metalúrgica, 1062, Parque Industrial Saltillo-Ramos Arizpe, Ramos Arizpe 25900, Mexico;Instituto Tecnológico de Saltillo, Blvd. Venustiano Carranza, 2400, Col. Tecnológico, Saltillo 25280, Mexico;International Lead Zinc Research Organization, Inc., 1822 East NC Highway 54, Durham, NC 27713, USA;

关键词: advanced high-strength steels;    dual-phase steel;    intercritical transformation;    CCT diagrams;    continuous annealing;    microstructure;   

DOI  :  10.3390/met8090674

来源: DOAJ

【 摘 要 】

The phase transformation kinetics under continuous cooling conditions for intercritical austenite in a cold rolled low carbon steel were investigated over a wide range of cooling rates (0.1–200∘C/s). The start and finish temperatures of the intercritical austenite transformation were determined by quenching dilatometry and a continuous cooling transformation (CCT) diagram was constructed. The resulting experimental CCT diagram was compared with that calculated via JMatPro software, and verified using electron microscopy and hardness tests. In general, the results reveal that the experimental CCT diagram can be helpful in the design of thermal cycles for the production of different grades of dual-phase–advanced high-strengh steels (DP-AHSS) in continuous processing lines. The results suggest that C enrichment of intercritical austenite as a result of heating in the two phases (ferrite–austenite) region and C partitioning during the formation of pro-eutectoid ferrite on cooling significantly alters the character of subsequent austenite phase transformations.

【 授权许可】

Unknown