On the issue of selecting and optimizing parameters of continuous laser welding of cast iron

OBRABOTKAMETALLOV Vol. 23 No. 3 2021 technology Fig. 3. Calculated shape of the weld seam depend- ing on laser power and welding speed: a – welding speed 35 mm/s; b – laser power 1 kW Ta b l e 4 Orthogonal array, natural values and corresponding response values № x 1 * x 2 * Laser Power, kW Welding speed, mm/s Penetration ( y 1 ), mm Width ( y 2 ), mm Convexity ( y 3 )**, mm Hardening area ( y 4 ), mm 1 1 1 0.6 14 0.04 1.53 –0.34 0.12 2 1 2 0.6 35 0.48 1.04 –0.03 0.10 3 1 3 0.6 56 0.91 0.56 0.29 0.08 4 2 1 0.95 14 1.05 1.92 –0.06 0.15 5 2 2 0.95 35 1.49 1.44 0.25 0.13 6 2 3 0.95 56 1.92 0.96 0.57 0.11 7 3 1 1.3 14 2.07 2.31 0.22 0.18 8 3 2 1.3 35 2.5 1.83 0.53 0.16 9 3 3 1.3 56 2.93 1.35 0.85 0.14 Note: * coded values of laser power and welding speed; ** a minus means concavity of the weld seam − + ζ − x = − + ζ − 0 0 0 0 min min max max max max i j i ij i j i ij ij i ij i j i ij x x x x x x x x where x i 0 – is an ideal normalized result of the i-th parameter, x i 0 = 1; ζ – is the coefficient of difference, in this study it is taken ζ = 0,5. The grey relational grade is determined by averaging the grey relational coefficients: ∑ = g = x 1 1 m j ij i m