Investigation of an impulse laser welding of thin plate constructions from different steels

Abstract

The investigation of laser welding of pearlitic steel 65Г (65Mn4 LST EN 10027-1) of 0.30 mm thickness with austenite-martensite steel 07X16H6 (X7CrNi 16-6 LST EN 10027-1) of 0.25 mm thickness was carried out. The ruby laser was used. The pulse frequency was 15 Hz and the power varied from 5.50 to 7.08 J, the used welding rate was from 1.35 till 1.80 mm/s. The angle of curvature of the welded samples was determined and metallography of the welds was investigated. It is established, that the best results of the samples bending are obtained when linear energy of welding is minimal. Metallgraphcal investigations show, that in the thermal influence zone the region from the side of carbon steel 65Г the diminished carbon content is found (it etches better). Pores and cracks are observed in the weld when the deviation from the optimum welding conditions takes place in the weld. This makes reliability and exploiting properties of the joint worser. It is the best to conduct the welding with a small displacement to the side of more alloyed steel.