Corrosion Resistant Marking of Stainless Steel
by using Picosecond Laser
The stainless steel does not readily corrode, rust or stain with water as ordinary steel does. However, laser marking can accelerate corrosion even of stainless steel. Nevertheless, it has been demonstrated that laser marking by using ultra-short (picosecond) laser pulses can produce rust free markings and even enhance resistance to corrosion for some grades of stainless steel like 316L grade.
The laser treatment of 316L grade stainless steel by using picosecond laser pulses leads to the darkening and brightening of samples depending on type of the steel. Darkening or whitening of the stainless steel saample strongly depends on the laser power, scanning speed.
The demonstrated corrosion resistant colouring method has promising applications like marking of logo, serial numbers, QR, bar and data matrix codes on mobile phones, wristwatches, jewellery and medical instruments.