Analysis on Fiber Laser Welding of MS1470 Steel

MS1470 steel is mainly used in the automotive industry, which has high strength, light weight and low cost. However, there always appear grains coarsening, brittle increasing, lower intensity and other issues. To solve this problem, we have analyzed the welding process, the fracture morphology and microstructure etc. The results shown that the microstructure were mainly ferrites and lath martensites. However, grains coarsening in the HAZ were serious, and fracture failure also occurred in the heat affected zone. Meanwhile, MS1470 steel had formed a small amount of pores during rolling process, which also is an important reason for cracks formation.