Friction stir spot welding was used to join two advanced high-strength steels using polycrystalline cubic boron nitride tooling. Numerous tool designs were employed to study the influence of tool geometry on weld joints produced in both DP780 and a hot-stamp boron steel. Tool designs included conventional, concave shouldered pin tools with several pin configurations; a number of shoulderless designs; and a convex, scrolled shoulder tool. Weld quality was assessed based on lap shear strength, microstructure, microhardness, and bonded area. Mechanical properties were functionally related to bonded area and joint microstructure, demonstrating the necessity to characterize processing windows based on tool geometry.
Revised: June 23, 2010 |
Published: December 28, 2009
Citation
Hovanski Y., M.L. Santella, and G.J. Grant. 2009.Friction Stir Spot Welding of Advanced High Strength Steels. In Friction Stir Welding and Processing V: Proceedings of Symposia Sponsored by the Shaping and Forming Committee of the Materials Processing & Manufacturing Division of TMS (The Minerals, Metals & Materials Society), February 15-19, 2009, San Francisco, California, edited by RS Mishra, MW Mahoney and TJ Lienert, 161-170. Warrendale, Pennsylvania:TMS - Minerals, Metals & Materials Society.PNNL-SA-65936.