Laser Forming of Tailored Blanks of High Tensile Strength Steels

Abstract

Tailor welded blanks with two different materials (SPCC-SPFC980Y) were V bent by laser forming which is a bending method with thermal stress induced by rapid heating by means of laser irradiation, and it is suitable for bending of large spring back sheets since spring back is not affected. Forming conditions for SPCC part and SPFC980Y part were changed. A 50W CW YAG laser was employed with laser scanning number of 10 and defocus length of 25mm. When same laser power (38W) was employed for SPCC and SPFC980Y parts, bending angle of SPCC part was greater than that of SPFC980Y part. However, when laser power was 40W for SPFC980Y part and 36W for SPCC part, the bending angle of both parts were almost same and this means constant bending angle was obtained by controlling the laser power. Uniform bending angle was also obtained by controlling the laser scanning velocity as well as the laser power.