A crosshead is a block or bar between the piston and the connecting rod of an engine that prevents the piston from moving from side to side and damaging the piston and cylinder. The crosshead guides the piston rod, protecting it from the sideways forces of the connecting rod. During abnormal operation the cross head comes in contact with sides of the cylinder and an absence of coating will damage the cross head as well as the cylinder.
Babbitt is a soft metal deposited on cross head and cross head shoes through Twin Wire Arc spray and Wire Flame spray coating process. These coatings act as a sacrificial layer meant to provide protection to piston rod and its sub-assemblies during abnormal operation or vibration. The base metal is prepared by machining threads on the coating surface to facilitate better bonding. After coating the surface is machined to achieve desired size and surface finish. Required NDT’s are performed to ensure that the coating does not have any defects.
|Coating Properties||PIC WC02|
|Micro Hardness||20 – 30 HV0.3|
|Porosity||6 - 10%|
|Bond Strength||Up to 3000 Psi|
|Finish Coating Thickness||2 to 2.5mm|