Investigation of Laser Micro Welding Data for Stainless Steel Using Hablanian Plot

Abstract

We have analyzed the laser micro welding data for stainless steel (SUS304) by using the Hablanian plot. We have determined the standard fitting curve, which is obtained by fitting the laser micro welding data with a cubic polynomial, and the fitting difference (ΔLog₁₀(Vd/K)) in Log₁₀(Vd/K) between the standard fitting curve and the corresponding experimental data. When ΔLog₁₀(Vd/K) is equal to 0, we can precisely predict penetration depths by using the standard fitting curve. We have investigated the dependences of ΔLog₁₀(Vd/K) on penetration depth, welding speed, laser power, and spot diameter. The following findings could be derived. (1) The standard fitting curve for micro welding was mostly corresponding to that for macro welding. (2) ΔLog₁₀(Vd/K) had negative values above penetration depth of ~0.7-0.8 mm. The deeper penetration depth became, the more markedly ΔLog₁₀(Vd/K) decreased. (3) It is essential for accurate prediction of penetration depth to collect welding data for each spot diameter and to obtain the fitting difference ΔLog₁₀(Vd/K) for each spot diameter. (4) We showed that prediction of penetration depth with correction using ΔLog₁₀(Vd/K) data for each spot size is available.