2019 年 26 巻 3 号 p. 74-78
In order to prove the validity of prediction of penetration depths using Hablanian plot, experimentally-obtained penetration depths with CW fiber lasers of 0.01~10 kW were compared with those predicted by Hablanian plot. The experimental results with ~900 data points for stainless steel plates were obtained from bead-on-plate welding tests performed in the laser job shop. Laser power, welding speed and spot diameter were varied as laser conditions. The experimental results expressed by Hablanian plot with two dimensionless parameters(Log10(Vd/K)and Log10(P(/ θtk)))were fitted by the 3th-degree polynomial fitting curve(standard fitting curve). The fitting difference(ΔLog10(P/ θtk))between the standard fitting curve and thecorresponding experimental result was larger at deeper penetration depths, and resulted in the error of prediction. This fitting difference at a given Log10(Vd/K)was calculated and obtained as a function of laser power. The error of prediction after correction for fitting difference was lower than that before correction. Thus, we showed that correction for fitting difference was essential for accurate prediction of penetration depth using Hablanian plot.