IRON-BASED ALLOY FOR USE IN MOLDS FOR PLASTICS

The use of a chromium-containing martensitic alloy for plastic molds is described. The use properties of a thermally-treated plastic mold of a hardness of at least 45 Rockwell C are improved by an iron-based alloy including, in weight-%: C 0.25 to 1.0, preferably 0.4 to 0.8; N 0.10 to 0.35, preferably 0.12 to 0.29; Cr 17.0 to 25.0, preferably 17.0 to 19.0; Mo 0.5 to 3.0, preferably 0.8 to 1.5; and V 0.04 to 0.1, preferably 0.05 to 0.1, where the sum of the concentration of carbon and nitrogen results in a value of, in weight-%, at least 0.5 and no more than 1.2, preferably at least 0.61 and no more than 0.95, the remainder including iron and melt-related impurities.