Refers to steel that has undergone heat treatment processes to increase its hardness and strength, making it suitable for high-stress applications. There are several types of hardened steel, each tailored for specific uses based on their composition and heat treatment methods:
1. Carbon Steel:
- High Carbon Steel: Contains 0.6% to 1.4% carbon, offering high hardness and strength after heat treatment. Commonly used for tools and knives.
- Medium Carbon Steel: Contains 0.3% to 0.6% carbon, providing a balance of strength and ductility. Often used in automotive components.
2. Alloy Steel:
- Chromium Steel: Enhances hardness and wear resistance, often used in gears and crankshafts.
- Manganese Steel: Contains about 12-14% manganese, known for its high impact strength and wear resistance, used in mining equipment and railroad tracks.
- Nickel-Chromium Steel: Provides good toughness and strength, often used in heavy machinery and aerospace applications.
3. Tool Steel:
- D2 Steel: A high-carbon, high-chromium tool steel known for its wear resistance, used in cutting tools and dies.
- A2 Steel: An air-hardening tool steel that offers good toughness and is less prone to chipping, suitable for various cutting tools.
- O1 Steel: An oil-hardening tool steel that provides good hardness and wear resistance, commonly used for hand tools.
4. Stainless Steel:
- Martensitic Stainless Steel: Contains high levels of carbon and chromium, known for its hardness and corrosion resistance, used in knives and surgical instruments.
- Austenitic Stainless Steel: Less hard than martensitic grades, it can be hardened through cold working, used in food processing and kitchenware.
5. Case-Hardened Steel:
- Case-Hardening Process: A process that hardens only the surface of the steel, leaving the core softer and more ductile. Commonly used for gears, shafts, and other parts requiring wear resistance.
6. High-Speed Steel (HSS):
- High-Speed Steel: A type of tool steel that maintains its hardness at high temperatures, used in cutting tools and drills.
These different types of hardened steel offer various properties suited for specific applications, making them integral to many industries, from manufacturing to automotive and aerospace.