Heat Treatment Design for a QP Steel: Effect of Partitioning Temperature

Metals

Jessica Calvo¹  Marcel Carpio¹  José María Cabrera¹  Juan Pablo Pedraza²  Omar García² 

[1]Departament de Ciència i Enginyeria de Materials (CEM), EEBE, Campus Diagonal Besòs, Univesitat Politècnica de Catalunya, Av. Eduard Maristany 10-14, 08019 Barcelona, Spain

[2]TERNIUM México, Av. Universidad 992 Nte., Col. Cuauhtémoc, San Nicolás de los Garza 66450, Mexico

关键词: QP;    retained austenite;    low carbon steel;   

DOI  :  10.3390/met11071136

来源: DOAJ

【 摘 要 】

Designing a new family of advanced high-strength steels (AHSSs) to develop automotive parts that cover early industry needs is the aim of many investigations. One of the candidates in the 3rd family of AHSS are the quenching and partitioning (QP) steels. These steels display an excellent relationship between strength and formability, making them able to fulfill the requirements of safety, while reducing automobile weight to enhance the performance during service. The main attribute of QP steels is the TRIP effect that retained austenite possesses, which allows a significant energy absorption during deformation. The present study is focused on evaluating some process parameters, especially the partitioning temperature, in the microstructures and mechanical properties attained during a QP process. An experimental steel (0.2C-3.5Mn-1.5Si (wt%)) was selected and heated according to the theoretical optimum quenching temperature. For this purpose, heat treatments in a quenching dilatometry and further microstructural and mechanical characterization were carried out by SEM, XRD, EBSD, and hardness and tensile tests, respectively. The samples showed a significant increment in the retained austenite at an increasing partitioning temperature, but with strong penalization on the final ductility due to the large amount of fresh martensite obtained as well.

【 授权许可】

Unknown