Hardening steel is a process designed to improve its mechanical properties. There are a number of different hardening methods. An important process is case hardening, which is when the workpieces are carburized to give them a hard edge layer up to 4 mm thick, but their cores remain tough. The parts are heated to what is referred to as the tempering temperature and then quenched. This can be done using water, oil, molten salt, or inert gases.
The hardened steels listed below are often used in the industry and pose particular challenges:
- 100Cr6 60HRC: Type 100Cr6 steel (material number 1.3505) is part of the ISO H. It is used in the automotive industry and mechanical engineering (rolling bearings). 100Cr6 is relatively tough, making it resistant to wear. It also remains highly stable while being tempered, and rarely deforms during heat treatment. The steel also boasts a high resistance to contact fatigue. There is a risk of high tool wear and heat stress during machining.
- EN-GJL-200: Also called GG20, the material is a hard-cast iron grade from the ISO H group. It is a typical material used for gearing, and is known for its high thermal conductivity, good damping properties, and high degree of rigidity. GG20 also wears out cutting tools relatively quickly. It is also quite a challenge to achieve the target dimensions on the component during the machining process. GG20 is widely used throughout the automotive industry.
- PM23: This material is also called 1.3344 PM, and is also part of the ISO H group. It is used in mechanical engineering. It is a high-speed steel that is very resistant to wear. The toughness and dimensional stability of PM23 make it the right choice for constructing stamping, cutting, forming, and machining tools. It is also important that it is machined using suitable tools and adequate process parameters.
Machining hardened steel places extremely high demands on the quality and condition of the cutting tools used. Regardless of whether you’re drilling, turning, or milling, machining hardened steels poses a technical challenge. As a recognized specialist, ZCC-CT also has the right tools for hard machining this class of materials in its portfolio.