EFFECTS OF OPTIMIZATION PARAMETERS ON FIBER LASER WELDING OF SMA490AW WEATHERING STEEL USING RESPONSE SURFACE METHODOLOGY

In fiber laser welding experiments with the SMA490AW weathering steel, 3-mm steel plates were laser welded in a butt joint using an ytterbium fiber laser. The experiment was conducted using a central composite design (CCD). The parameters for the laser fiber settings were: laser power: 1,800 W to 2,000 W, welding speed: 10 mm/s to 12 mm/s, focus position: -1.5 mm to 0.0 mm. The results were analyzed using analysis of variance (ANOVA) for penetration depth, ultimate tensile strength (UTS), and elongation (%EL). Key findings: penetration depth was affected by focus position, power, and speed. Maximum penetration depth was achieved with the following settings: focus position -1.5 mm, power 2,000 W, speed 10 mm/s. Ultimate Tensile Strength (UTS) was affected by power, speed, focus position, quadratic term of power (power²), and interaction terms of power* speed and power* focus position. Maximum UTS was achieved with the following settings: power 2,000 W, speed 12 mm/s, focus position -1.5 mm. Elongation (%EL) was affected by speed, focus position, and interaction term of speed*focus position. Maximum %EL was achieved with the following settings: speed 12 mm/s, focus position -1.5 mm. Optimum fiber laser welding conditions for SMA490AW included power: 2,000 W, speed: 12 mm/s, and focus position: -1.5 mm.