45^# steel interaction with DF laser beam in different gas flow

Experimental measurement was employed to study the effects of the DF high-power laser irradiation on 45# steel in different gas flow. The surface picture was analyzed and the temperature histories were measured. The effect of steel ablation was obvious and the temperature on the rear center of the coupon was highest in the tangential air flow. The experimental results showed that some melt was removed by the tangential gas flow, especially in the air flow where combustion played an important role in heating the material. The target was cooled after laser irradiation. According to the experimental results, a numerical model was established to simulate the irradiation effects of high power density laser on steel targets in different gas flow. The method of Element birth and death was employed to simulate the ablation effects of laser on steel targets in the air flow, where the effects of heat releasing by oxidation were included. The results of the numerical simulation agreed well with the experimental results. It explained the effects of the gas flow in the laser irradiation.