Core Shaft Categories

1. Propeller Shafts

   • Directly drive propellers, taking high torque and bending stress.
   • Materials: 42CrMo, 25Cr2Ni4MoV, or duplex stainless steel for corrosion resistance .
   • Manufacturing: Forging reduction ratio ≥4, with ultrasonic testing per Grade 3-D.
   • Scantling Standards: Dimensions follow ClassNK/Korean Register formulas.

2. Intermediate Shafts

   • Connect propulsion segments with rectangular/stepped profiles.
   • Materials: 45# steel, 34CrNiMo6, or 30CrMnSi .
   • Forging Advantage: Fibrous grain alignment enhances tensile/torsional strength vs. cast alternatives .

3. Thrust Shafts

   • Transfer propeller thrust to hull structure via H-shaped sections.
   • Feature Zone III heat treatment for uniform hardness .

4. Crankshafts

   • Convert piston motion to rotation; critical for diesel engines.
   • Forging Methods:
   • Traditional: Free forging + welding.
   • Advanced: Semi-built forging for >10,000-ton vessels .