Microstructure and Mechanical Properties of Resistance Spot Welded Advanced High Strength Steels

Integration of advanced high strength steels (AHSS) into the automotive architecture has brought renewed challenges for achieving acceptable welds. Resistance spot welding (RSW) is the primary method used in welding automotive structures, which has resulted in a demand to better understand RSW of AHSS. The varying alloy contents and processing techniques used in their production has further complicated this initiative. The current study examines resistance spot welding of AHSS including 590R, DP600, DP780 and TRIP780. HSLA material is also included to represent conventional high strength steels and benchmark AHSS performance. The mechanical properties and microstructure of these resistance welded steel alloys are detailed. Furthermore, a relationship between chemistries and fusion zone hardness is produced.