Comparing the Effectiveness of Laser Marking on Different Materials

The article compares the laser marking results of three common stainless steel materials, 304, 316, and 430, and analyzes the differences in marking clarity, oxidation reactions, and durability.

Why does the material affect the results?

When we mark stainless steel with a laser, we often find that some materials are marked clearly, while others are blurred and gray.In fact, this is closely related to the composition of the material itself. For example, 316 grade stainless steel, which has a high chromium content, is more susceptible to oxidation, whereas ferritic stainless steels like 430 exhibit less noticeable color changes when engraved.

Preparing test materials and equipment.

This time we specially brought three kinds of the most commonly used stainless steel sheets.

Common stainless steel materials.

• 304 stainless steel (18 % chromium + 8 % nickel).

316 stainless steel (16 % chromium, 10 % nickel, 2 % molybdenum).

• 430 grade stainless steel (17 % chromium).

The test used a 20W fiber laser with a speed of 700mm / s and a frequency of 20kHz, so that the difference in the materials themselves could be more easily seen.

Actual results of the two methods.

Color contrast performance.

The blackening effect is most pronounced on 316 stainless steel, which is as clear as Chinese calligraphy on white paper.304 appears dark gray, while 430 can also be identified, but it requires a close look to make out the markings.

The stability of the surface oxidation layer.

After repeatedly wiping them with an alcohol swab, it was discovered that the 316 mark was the most durable, and did not change color even after 10 or more wipes.The 304 mark began to fade after seven or eight wipes, while the 430 mark became very faint after three wipes.

The ability to produce finely detailed designs.

When carving a two-dimensional code 0.5 mm wide, 316 stainless steel allows the code to be read 95 % of the time, whereas 304 stainless steel can only do so about 85 % of the time. 430 stainless steel is even worse, because the difference between the background and the markings is so small that the angle of the scanner has to be adjusted.

Suggestions for daily use.

If you need outdoor signs or long-lasting tool markings, I recommend 316.For temporary labels or cost-sensitive products, 304 is sufficient.As for 430 stainless steel, unless you don't care about the surface effect, it is better to use chemical etching.

Finally, I want to remind everyone to first try out the laser on scraps of material before actually engraving your workpiece.The composition of the materials used by different manufacturers might be slightly different, and especially the performance of recycled materials is different from that of virgin materials. We can discuss how to tell the quality of materials in more detail next time.