The 3D-printed stamps with laser hardening had a lifespan three times longer than the stamps used earlier. In addition to improved service life, the manufacturing cost is significantly lower.

At SSAB's operations in Borlänge, Signode straps are used to prevent the coils from opening and to ensure safe shipping. The straps are held in place by a stamping operation which locks the strap ends together. Some of the strapping machines are old and the supplier can no longer supply spare parts. This problem prompted the maintenance department to look for new supply chains for spare parts. One method that can quickly produce parts is 3D printing, and this is what we decided to test.

Figure 1 The image to the left shows a coil that is strapped. The middle image shows what the strap looks like after punching. The image to the right shows the locking mechanism and the stamp that was produced with 3D printing and laser hardening  can be seen the middle of the image.

The blanks for the stamps were manufactured using 3D printing at SSAB in Oxelösund, Sweden. After printing, the stamps were processed to final tolerance and then sent for laser hardening of the wear surfaces.

"3D printing in combination with SSAB TS2 powder generates a material that is both hard and tough, and by laser hardening the material, we have obtained a product that has performed beyond expectations," says Jesper Vang, Head of Powder Technology at SSAB.

Figure 2: The part at the top is a 3D-printed blank and the part below it is a finished and laser-hardened stamp after use in production.

Work is now underway to identify more components in SSAB's various facilities where it is possible to take advantage of the benefits of 3D printing and laser hardening.

Laser hardening is based on a surface being heated by the energy from a laser beam and then rapidly cooled, i.e. quenched, by the surrounding material. The main advantage of laser hardening is that only the surface that needs increased hardness is hardened, which gives low energy input and thus minimal distortions.

If you want to learn more about our investment in steel powder and additive manufacturing, read more here