How to Mark Colors on Stainless Steel with Laser Engraver?

STYLECNC has focused on designing, developing and selling laser marking machines for over 10 years, which has rich experience of laser marking service for DIY personalized projects and custom engraving plans. We will guide you how to mark different colors on stainless steel with a MOPA fiber laser marking machine.

What is Color Engraving Machine?

Color engraving machine is a type of automatic laser marking system that uses the MOPA fiber laser generator to change the colors of the surface layer of the material, thereby obtaining items of different colors. MOPA is an acronym for Master Oscillator Power Amplifier. Compared with Q-switched fiber laser generators, MOPA laser generators are more intelligent nanosecond pulsed fiber lasers. For stainless steels, the colors of the marking pattern can be added with MOPA laser, and various texts and patterns can be edited at will. The fiber laser engraver is convenient and easy to use, environmentally friendly and pollution-free, with high engraving speed, which can greatly increase the added value of stainless steel products, enhance the market competitiveness of stainless steel products.

How Many Types of Stainless Steels can be Engraved with Colors?

Stainless steel can be defined as martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel based on the structure state. It can also be defined as chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel based on the composition. In addition, there are special stainless steels for pressure vessels.

How Does a Fiber Laser Engraver Mark Colors on Stainless Steel?

In some cases, the correct control of the laser beam emitted by MOPA laser generators can enable the laser engraver to mark clearly visible black and white or color marking patterns on stainless steel, chrome, and titanium. When the laser marks the stainless steel material, the color change of the surface layer of the material can be changed by adjusting the laser beam, so as to obtain the decorative effect of different colors.

The principle of laser color development of stainless steel is that by selecting appropriate parameters, using laser to heat the stainless steel material, at an appropriate defocus amount, high pulse frequency and other appropriate parameters, a colorless and transparent layer can be produced on the surface of the stainless steel. Oxide film, under the irradiation of light, the interference of incident light makes the surface of stainless steel show various colors. This layer of phantom marking layer generated on the stainless steel surface changes with different viewing angles, and the marking pattern will also change into various colors.

3 Ways to Make Colors on Stainless Steel

We should know that there are 3 different ways to make stainless steel coloration.

Step 1. Generate colored oxide.

Step 2. By the chemical, electro chemical or under the action of laser, a thin layer of colorless transparent film are generated on the surface of stainless steel, The oxide film thickness by precisely controlled. Because of diffraction effects, oxide films of different thicknesses can be presented in different colors.

Step 3. In the presence of a mixed state of colored oxide and oxide film.

The Relationship Between the Colors Change and the Laser Energy in the Stainless Steel Color Laser Marking.

Under the laser, the stainless steel table generated the laser heat effect. By the laser heat effect, we will get the relationship between the laser energy density and the film thickness is proportional to the laser energy density. With increase of laser energy, stainless steel surface color changed according to the following sequence of color change:

Orange-Red-Purple-Blue-Green, Blue-Blue, Green-Green-Yellow, Green-Yellow-Orange-Red.

So you can mark anything you want, such as text, logos, signs, patterns, pictures, etc. It is very easy and environmental protection without pollution, high marking speed, for the stainless steel industry, the color laser marking machine can make stainless steel projects value-added.