Mechanical Property Mapping for Dual Phase (DP) Steels

Setty M., Annasamy M., Cora Ö. N.

COST Action CA21121 MecaNano General Meeting 2023, Madrid, Spain, 26 - 27 April 2023, pp.1

  • Publication Type: Conference Paper / Summary Text
  • City: Madrid
  • Country: Spain
  • Page Numbers: pp.1
  • Karadeniz Technical University Affiliated: Yes


Advanced high strength steels (AHSS) offer various benefits for automotive applications including lightweighthing through use of thinner sheet blanks without compromising strength, and safety. Among di_erent AHSS grades, dual-phase steels offer improved strength and ductility thanking to their ferrite matrix (provides ductility) and martensite (provides strength). This study aimed to reveal the effect of deformation on the mechanical properties of two DP steel grades, namely DP 1000, and DP 1200 by employing maximum load-controlled indentation with a Berkovich type of indenter. The maximum indentation loading of 6 mN was employed and 400 indentations (20x20) were performed in matrix form and with 10 µm spacing. The loading scheme was loading for 5 s, holding it for 2 s, and then unloading at 5 s. To reveal the effect of deformation, the DP 1000 and DP 1200 materials in plate form were subjected to 3-point bending test that surpassed the yield point of the material. Then, two samples were extracted from the most deformed, and undeformed (or significantly less deformed) zones. The nanoindentation was applied both to deformed and undeformed sections of the investigated dual-phase steels. Hardness and modulus of elasticity values obtained are mapped for the investigated area. In addition, EBSD measurements were performed to establish microstructure-property relation. It was revealed that the Hardness values were relatively in a narrow range denoting the overall response of the microstructure rather than the ones for individual phases. In addition, the effect of deformation is more pronounced for DP 1000.