Laser hardening a press tool: wear-resistant, minimal distortion

Press tools for car body parts have to hold their shape, part after part. Only then will the panel gaps on the finished car be right as well.

However, the high-strength body sheets take quite a toll on the tool surface during forming. That’s why we laser-hardened the large, heavily stressed surfaces of one of these press tools. Tools like this are usually manufactured very close to final dimensions. Hardening processes that heat the entire tool cause more distortion, and with it more rework.

With laser hardening, only the surface layer of the areas that actually need hardening is heated. The laser beam follows the contour precisely, and its track width can be adjusted flexibly in the x and y directions during the hardening process. Quenching takes place through the volume of the tool itself, with no quenching medium. What remains is a hard, wear-resistant surface over a tough core. Because heat input is low, distortion stays low as well, and so does the effort required for rework.