Microstructure and Property of HD Die Steel With Unsmoothed Surface With Various Laser Parameters Original Research Article

The reticulate unsmoothed surfaces on HD die steel, which imitate the surface of soil-burrowing animals (such as the dung beetle, earthworm, pangolin, and ant) are produced with various laser parameters. The characteristics (including width, depth, area ratio, and volume), microstructure, and hardness of the unsmoothed units are studied. At the same time, the wear resistance of the material with an unsmoothed surface is measured. The results show that the width and volume of the unit increase, the microstructure becomes coarser, the hardness decreases, and the wear resistance improves with the increase of the current intensity and pulse duration within a certain range. However, there is little difference between the extent to which the wear resistance of the material increases and the unsmoothed surface, when the current intensity and pulse duration increase to some extent. The wear resistance of the unsmoothed material under 300 A or 20 ms is better in the experiments. The improving extent of the wear resistance lies in a combination of the characteristics, microstructure, and hardness of the unsmoothed unit. An unsmoothed material with better properties can be processed if the laser parameters are well matched.