Formability of Friction Stir Processed Dual Phase 600 Steel


13th Junior EUROMAT 2016, Lausanne, Switzerland, 10 - 14 July 2016, vol.1, no.1, pp.26

  • Publication Type: Conference Paper / Summary Text
  • Volume: 1
  • City: Lausanne
  • Country: Switzerland
  • Page Numbers: pp.26
  • Karadeniz Technical University Affiliated: Yes


Dual phase (DP) steels have good engineering properties such as high strength,deep drawability and high strain hardenability. Thus, they have been widely used especially in the automotive industry to reduce vehicle weight and improve car safety. However, automotive industry is still attempted to improve this steel for the

better formability. The properties of DP steels depend on volume fraction, microstructural morphology, the grain size and the carbon content. The mechanical and microstructural properties of these steels can be substantially improved by friction stir processing (FSP), which is one of the severe plastic deformation (SPD)

techniques thanks to altering in the morphology and grain refinement without changing chemical compositions of DP steels. The aim of this study is investigation formability properties in DP 600 steel subjected to FSP. They were subjected to one-pass FSP using a WC tool consisting of a shoulder having a diameter of 12 mm and a cylindrical pin with a diameter and length of 5 mm and 1.2 mm, respectively. The shoulder tilt angle was 2°, and the tool plunger downforce were kept constant at 5 kN. Stretch formability tests before and after FSP were performed using the Erichsen test technique, which is a well-established standard for studying theformability under biaxial strain conditions. The Erichsen test specimens with thedimensions of 13 mm × 13 mm × 0.7 mm were sectioned from the FSPed zone.There has not been a remarkable alteration on the formability behavior after FSP.The surface quality of the stretched samples was improved after FSP by grainrefinement. Also orange peel effect on the dome free surface of the base samplewas cons iderably reduced with grain refinement via FSP.