Application and Performance of C45 Steel in Modern Industry

Hydraulic cylinder piston rod

C45 steel (USA 1045 steel) is a commonly used medium-carbon structural steel. It is widely used in industry due to its good comprehensive mechanical properties and processing properties. The following is its specific application and performance analysis:

1. Basic Characteristics of C45 Steel

  • Composition: Carbon content is about 0.42%-0.50%, containing a small amount of manganese, silicon and other elements, belonging to medium carbon steel.
  • Mechanical properties: After heat treatment, the tensile strength can reach 600-800 MPa, and the hardness is about HRC 20-30 (HRC 40-50 after quenching and tempering).
  • Heat treatment: Normalizing and quenching and tempering (quenching + tempering) are often used to improve strength, and surface quenching enhances wear resistance.

2. C45 Steel Industrial Application Fields & Performance

1. Mechanical manufacturing

  • Application: shaft parts (drive shaft, main shaft), gears, couplings, connecting rods, bolts and other high-stress parts.
  • Performance:
    – High strength: After quenching and tempering, it can withstand large alternating loads and is suitable for parts with high-speed rotation or torque transmission.
    – Wear resistance: After surface quenching, the hardness is improved, which prolongs the service life of parts such as gears and cams.
    – Machinability: Good cutting performance, suitable for precision turning and milling.

2. Automotive industry

  • Application: crankshaft, steering knuckle, half shaft, differential gear and other power transmission parts.
  • Performance:
    – Fatigue strength: C45 steel after quenching and tempering has excellent fatigue resistance and is suitable for automotive parts that run under long-term high load.
    – Cost-effectiveness: Compared with alloy steel, it is cheaper and meets the needs of mass production.

3. Molds and tools

  • Application: injection mold base, cold stamping die template, simple tool (such as drill handle, fixture).
  • Performance:
    – Rigidity: Medium carbon steel has moderate hardness and is suitable for low-complexity molds, but its wear resistance is lower than that of special mold steel (such as Cr12).
    – Economical: In scenarios where high wear resistance is not required, C45 steel can replace high-priced materials to reduce costs.

4. Building and engineering structures

  • Application: non-welded structural parts such as high-strength bolts, flanges, and supports.
  • Performance:
    – Weldability restrictions: Due to the high carbon content, welding requires preheating (150-250℃) and post-heat treatment to prevent cracks.
    – Tensile strength: better than low carbon steel, suitable for structural parts bearing static loads.

5. General parts

  • Application: hydraulic cylinder piston rod, pin shaft, bushing, gasket, etc.
  • Performance:
    – Comprehensive performance: taking into account both strength and toughness, surface chrome plating or carburizing treatment can further improve corrosion resistance and wear resistance.
    – Easy processing: excellent cutting performance in the annealed state, suitable for mass production of standard parts.

3. Summary of the Advantages & Disadvantages of C45 Steel

  • Advantages:
    – Low cost and high cost performance.
    – Flexible heat treatment, performance can be adjusted through different processes.
    – Excellent processing performance, suitable for a variety of forming processes.
  • Limitations:
    – Poor weldability, strict process control required.
    – Average corrosion resistance, surface protection treatment required.
    – Performance degrades under high and low temperature environments, not suitable for extreme working conditions.

4. Comparison of C45 Steel With Other Materials

  • vs. Low carbon steel (such as Q235): C45 has higher strength, but poor weldability, and is suitable for high-load non-welded parts.
  • vs. High carbon steel (such as C60): C45 has better toughness and is not easy to crack, which is suitable for scenes with comprehensive mechanical properties.
  • vs. Alloy steel (such as 5140): 5140 has higher strength and better hardenability, but C45 has lower cost and is suitable for general use.

5. Summary

Due to its strength, processability and economy, C45 steel has become a “universal steel” in the fields of machinery manufacturing, automobiles, molds, etc. Through reasonable heat treatment and surface treatment, its application range can be further expanded. It is an ideal choice for medium and low complexity and medium load conditions. However, in extreme environments or high precision requirements, higher performance materials need to be selected.

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