Microstructures and Mechanical Properties on Laser Welded Joints of Automotive High Strength Complex Phase Steel
Reducing car’s weight has become an important goal for automobile industry. Laser welding of automotive high-strength steel plays a significant role in producing light weight cars. Experiments of CO2 high power laser welding of 1000MPa grade complex phase steels with a thickness of 3mm for automobile were performed using a 15 KW CO2 laser. The macrostructure and microstructure of the welded joint were examined by optical microscope. Mechanical properties of the welded joint, fusion zone and base metal were assessed by microhardness distribution across the welded joint, uniaxial tensile test and charpy V-notch impact test. Fractographs of the impact specimens were studied by scanning electron microscopy (SEM). It is found that the fusion zone has a higher toughness than that of the base metal and fusion line. The test results show good mechanical properties of laser welds that can meet the technical requirements for automobile Industry.
Zhengyi Jiang and Chunliang Zhang
L. H. Hu et al., "Microstructures and Mechanical Properties on Laser Welded Joints of Automotive High Strength Complex Phase Steel", Advanced Materials Research, Vols. 97-101, pp. 3957-3962, 2010