4-stroke cylinder covers material is high-tensile nodular cast-iron.Good enough tensile strength of welding joint can be achieved only by using special process - welding in oven
The process is homogeneous and stress-free due to extreme high temperature, close to melting point.
Using this process typical problems are avoided:
- No welding stresses
- No structure mixture
- No hardness jump in welding joint and heat affected zone
A lot of mechanical tests in laboratory were performed to test process results.
Reconditioning of cylinder covers consist of- Cleaning & Inspection
- Pressure testing
- Landing surface NDT (MT)
- Measurements & Recording
- All fittings removal
- Welding defects
- Mechanical treatment
- Control pressure testing
- Assembling
- Valves maintenance
- Painting
- Final parameters recording
Full 4-stroke cylinder covers reconditioning program includes:
- repair of fires side defects
- repair of cooling space defects.
- valve seats pockets restoration
- Valve cage pockets restoration
- Landing surface re-building.