STEELS.

Abstract

The processes developed for molding plastics and the different processing properties of the plastics lead to different types of stresses, which must be taken into consideration not only in the construction but also in the selection of the materials required for molds. As a material, steel has ideal qualifications, since its properties can be modified by alloying elements, by special production processes and by heat treatments and can be adjusted to various stresses. Moreover, the possibility exists of employing surface treatments to add to the already advantageous properties of the steels and, in so doing, fulfill the requirements for a long service life and an economical manufacture. Mold steels can be divided into case hardening steels, nitriding steels, quenched and tempered tool steels, fully hardening steels, corrosion resistant steels, maraging steels and hard material alloys. These are described to help in the selection of the correct steel.