The investigation of joinability characteristics in the laser welding method couples of AISI 304-430 stainless-AISI 1010 steel

In this study, the joining characteristics of AISI 304-430 stainless-AISI 1010 low carbon steels by using laser welding technique were investigated experimentally. Dissimilar materials copules from AISI 430-1010, AISI 304-1010 and AISI 430-304 steels were joined by laser welding with welding powers of 2000-2250-2500 W and welding speeds of 100, 200 and 300 cm/minute under argon and also helium atmosphere. Metallographic and mechanic of tests were carried out to determine welding qualities of the samples. Welding regions of the samples were examined by optic microscope, SEM and the intermetallic phases formed were determined by EDS and X-Ray analysis. Mechanical strength of welded samples were found by tensile test. Microhardness distributions of weldmants were also measured by microhardness test. The result of experiments showed that by increasing of welding speeds the widths of the welding zone and heat affected zone (HAZ) decreased. On the other hand, by increasing of welding powers the widths of the both zones increased. Microhardness values rised along the interface of the welded pairs depending on the increase in the welding power and welding speed. The increased with the increase in welding power the chromium-carbon diffusion in AISI 430/AISI 1010 steel pairs, the chromium-nickel-carbon diffusion in AISI 304/AISI 1010 and AISI 430/AISI 304 steel pairs welding interfaces. However it decreased with the welding speed. At elevated welding powers the tensile strengths of samples the increased with the increase in welding power and critical cooling rate. However it decreased with the welding speed. The best joints were obtained under the helium atmosphere in AISI 430/AISI 1010 steel pairs with a welding power of 2250 W and a welding speed of 200 cm/minute, AISI 304/AISI 1010 steel pairs with a welding power of 2500 W and a welding speed of 100 cm/minute, AISI 430/AISI 304 steel pairs with a welding power of 2500 W and a welding speed of 100 cm/minute.