Simulation and process optimization for laser marking of submillimetre rasterizing 2D code on stainless steel

Abstract

The simulation and process optimization for laser marking of submillimetre rasterizing 2D code on stainless steel are investigated. For 50CrVA stainless steel, the temperature field of material during laser marking is obtained by numerical modeling. The results show that temperature change in the depth direction and oxidation degree of laser radiation region are the fundamental reasons for the contrast of 2D code, but the temperature change occurs in the radius direction for the print growth. The threshold of laser average power and [Formula: see text] frequency for an identifiable submillimetre 2D code are, respectively, 3.0 W and 100 KHz, which matches the simulation well within normal operating conditions. It is also found that an increase of the pulses number effectively improves the contrast and the appearance consistency of modules in DM code. Besides, corrosion tests show that the corrosion resistance of submillimetre 2D code is greatly improved by covering a layer of transparent polyurethane coating. Finally, a sample of submillimetre 2D code marked on cylindrical tool with diameter of 1 mm is obtained. In conclusion, the method could obtain submillimetre code with high reading quality and corrosion resistance by minimizing the characteristic edge over-burn effects, which provides theoretical basis and experimental method for identification of small parts.