The temperature during ion implantation is well known to influence the microstructure of ionbombarded steels. In the course of our studies on metal-forming tools we could demonstrate the great importance of an additional moderate heat treatment subsequent to the ion implantation. Wear of heat-treated metal-forming tools was up to four times lower than in the as-implanted state. This effect was studied further in a systematic way. The production simulation processes "upsetting between plane parallel dies" and "backward extrusion of cans" were used as model processes for causing tool wear. Extrusion punches and upsetting dies were implanted with nitrogen, boron and metal-nitrogen combinations. The implantation dose was varied and the tools were heat treated after the implantation in the 200-300 ยฐC temperature region. The tool wear was measured by means of standard techniques during the metalforming process up to a maximum production of 20 000 parts. The results are discussed in the light of new ideas on the microstructure of implanted steels and compared with recent relevant M6ssbauer studies.