S45C Carbon Steel Sheet: Properties and Applications S45C is a medium-carbon steel widely used in industrial applications due to its balanced mechanical properties, machinability, and affordability. As a high-quality carbon steel sheet, it contains approximately 0.45% carbon, which provides a good combination of strength and ductility. This material is commonly supplied in hot-rolled or cold-rolled conditions, with surface finishes ranging from rough to smooth, depending on processing methods. Chemical Composition and Mechanical Properties The chemical composition of S45C carbon steel includes carbon (0.42–0.48%), manganese (0.60–0.90%), silicon (0.15–0.35%), phosphorus (≤0.030%), and sulfur (≤0.035%). The controlled carbon content ensures moderate hardness and tensile strength while maintaining reasonable weldability and formability. Typical mechanical properties of S45C steel sheets include: - Tensile Strength: 570–700 MPa - Yield Strength: ≥345 MPa - Elongation: ≥16% (depending on thickness) - Hardness: 170–220 HB (Brinell hardness) Heat Treatment and Machinability S45C responds well to heat treatment processes such as quenching and tempering, which enhance its hardness and wear resistance. Normalizing improves grain structure uniformity, while annealing increases machinability by reducing internal stresses. The steel’s machinability is considered good, though tool wear may increase at higher hardness levels. Applications Due to its strength and versatility, S45C steel sheets are used in various industries, including: - Automotive: Gears, shafts, and structural components - Machinery: Bolts, nuts, and hydraulic parts - Construction: Support frames and brackets - Tooling: Dies and molds (after heat treatment) Advantages and Limitations Advantages: - Cost-effective compared to alloy steels - Good balance of strength and ductility - Suitable for heat treatment to modify properties Limitations: - Lower corrosion resistance (requires coatings or plating) - Reduced toughness at very high carbon levels Conclusion S45C carbon steel sheets offer a practical solution for applications requiring moderate strength and machinability. Proper heat treatment and surface protection can further enhance performance, making it a reliable choice for industrial and mechanical components.