Through-hardenability and edge stability are achieved by alloying with Chromium, Manganese and Molybdenum. Steels with Nickel, Copper and Aluminium are age-hardenable and show favorable dimensional stability and weldability. These steels are usually supplied in the as heat-treated condition to approx. 30 to 44 HRC. Omission of further heat treatments improves cost-effectiveness and logistics in toolmaking.
Steels in this group are specially designed for use as tool steels in plastics processing.
Quenched and tempered steel is low-alloy stainless steel that achieves high tensile and fatigue strength combined with good toughness through quenching and tempering. In most cases, these steels are supplied by the steel supplier already pre-tempered and then used in this condition in tool production. By eliminating further heat treatment steps in the course of tool production, the cost-effectiveness and logistics in toolmaking can be significantly improved. The supplied hardness of approx. 30 to approx. 40 HRC is a good compromise between machinability, wear resistance and compressive strength (edge stability), which is sufficient for many applications in plastics processing. Higher tempering strengths are also used in special cases.
The carbon content is approximately between 0.3 and 0.4 %. The different alloy contents of chromium, manganese, molybdenum and nickel are very precisely matched to the respective application and have a particular influence on larger cross-sections. The weldability of these steels is limited. Coordinated sulphur contents are used on a case-by-case basis to improve machinability.
In the production of these steels, particular consideration is given to the requirements of plastics processing with regard to polishability and corrosion resistance in terms of purity, homogeneity and analysis balance.
Precipitation hardening steels in this group are special steels with alloying additions of Cu and Al, with excellent properties, in particular high toughness and good dimensional stability and good weldability. This group of steels achieves a martensitic microstructure with a higher Ni content combined with a low C content. Alloying elements such as Cu and Al are used to achieve hardenable alloy systems, whereby an increase in strength up to max. 44 HRC is achieved through the precipitation of intermetallic compounds from the martensite during heat treatment. The heat treatment of these steels is simple and minimises distortion and consists of a solution heat treatment with a final hardening treatment at temperatures in the region of approx. 500°C. Such steels are supplied pre-hardened or solution-annealed.