LASER WELDING METHOD OF HIGH STRENGTH STEEL SHEETS FOR MANUFACTURE OF TAILED WELD BLANK PARTS

摘要

A laser welding method of high strength steel sheets for manufacturing tailed welded blank parts is provided to use 60 kg/m^2 grade dual phase steel sheet(1.4t)+45 kg/mm^2 grade steel sheet(1.0t) or 60 kg/mm^2 grade dual phase steel sheet(1.4t)+45 kg/mm^2 grade steel sheet(0.7t) in a process of manufacturing automobile parts by welding the cut dissimilar steel sheets after cutting two or more dissimilar steel sheets to a predetermined size. In a method for manufacturing tailed welded blank parts by welding 60 kg/mm^2 grade dual phase steel sheet(1.4t)+45 kg/mm^2 grade steel sheet(1.0t) or 60 kg/mm^2 grade dual phase steel sheet(1.4t)+45 kg/mm^2 grade steel sheet(0.7t) using a Nd:YAG laser welder that is set to an output of 3.2 kW, a shielding gas(Ar) rate of 20 L/min, a gas injection angle of 30 degrees, and a focal radius of 0.30 to 0.35 mm, a laser welding method of high strength steel sheets for manufacturing tailed welded blank parts comprises performing laser welding of the 60 kg/mm^2 grade dual phase steel sheet(1.4t)+45 kg/mm^2 grade steel sheet(1.0t) or 60 kg/mm^2 grade dual phase steel sheet(1.4t)+45 kg/mm^2 grade steel sheet(0.7t) at a speed of 6.6 to 7.2 mpm.