Investigation on microstructural features and tensile shear fracture properties of resistance spot welded advanced high strength dual phase steel sheets in lap joint configuration for automotive frame applications

Journal of the Mechanical Behavior of Materials

Raja Selvaraj¹  Sivaraj Paramasivam²  Sonar Tushar³  Rajarajan Chakkaravarthi⁴  Mathiazhagan Nallusamy⁴ 

[1] Central Library, Alagppa University, Karaikudi –630 003, Tamil Nadu State, India;Centre for Materials Joining and Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar –608 002, Tamil Nadu State, India;Centre for Welding and Additive Manufacturing (C-WAM), Department of Mechanical Engineering, G. S. Mandal’s Maharashtra Institute of Technology, Aurangabad-431010, Maharashtra State, India;Department of Mechanical Engineering, Meenakshi Ramaswamy Engineering College, Thathanur-621804, Tamil Nadu State, India;

关键词: resistance spot welding;    advanced high strength steel;    tensile shear fracture load;    microhardness;    microstructure;   

DOI  :  10.1515/jmbm-2022-0006

来源: DOAJ

【 摘 要 】

The main objective of this research paper is to study the microstructural features and mechanical properties of resistance spot welded advanced high-strength steel of dual phase grade in lap joint configuration which is mainly employed in sheet form for fabrication of the automotive structure. Resistance spot welding (RSW) being a solid-state welding (SSW) process is used to overcome the problems in fusion welding of AHSS-DP steel such as heat affected zone (HAZ) softening, solidification cracking and distortion which significantly deteriorates the mechanical properties of AHSS-DP800 steel joints. The straight lap (SL-TSFL) and cross lap tensile shear fracture load (CL-TSFL) of spot joints were evaluated. Optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques were used to characterize the weld nugget. The X-ray diffraction (XRD) results are also presented for phase identification in the weld nugget. The fracture surface of failed TSFL specimens was analyzed using SEM. The lap joints made using RSW disclosed superior SL-TSFL, CL-TSFL, and WNZH of 21.7 kN, 17.65 kN, and 589 HV0.5 The superior joint strength and hardness of the weld nugget zone are correlated to the evolution of lath martensite in the nugget zone.

【 授权许可】

Unknown