HVOF SPRAY ON EN31 BEARING STEEL SHAFTS

[Zanitech]

Can EN 31 steel be HVOF sprayed?

The HVOF coating needs to give better wear and crack resistance than chrome plating. It needs to withstand constant pressure of 150 tons.

The component is a back up roll shaft in a anti coil set roll assy for a galvanizing plant coating sheets.the back up rollers smooth out the kinks. There is not much heat involved as it has already cooled down by the time it reaches the assembly.

[Stephen Booth]

Hi Zanitech,

Are you spraying the bearing area of the back up shaft?

If so you would be good to discuss with the customer maintenance department, or the local SKF representative too, as the maintenance and installation of the bearing, will be critical to the success of the repair.

If this is the same component as I have seen, repaired before, you need to have a good understanding with the customer on the "fit" and surface finish of the coating. The inner race of the bearing is actually lubricated, and needs to slip a bit during the times the back up roller is under heavy load.

Do a websearch on Back up rollers, and write your warranty to the customer to protect yourself against their errors.

Actually I would go with an HVOF Chrome Carbide or WC coating, ground at a pretty good finish, with correct tolerances.