Carbon Steel Padeyes welding to Stainless Steel Frame

[StructuralNomad]

Dear Community Members,

Can a carbon steel padeye (Fy = 250 MPa/345 MPa) be welded to a Stainless Steel Frame (SS316) to facilitate lift operation? Are there any restrictions that will render the payeye not fit for reuse should the frame need to be replaced at the end of service life?

Thanks and Regards

 

[dhengr]

StructuralNomad:
If the frame has to be stainless steel, shouldn’t the padeyes which might need to be used years later also be stainless steel, for all the same reasons as the frames. The two materials can be welded together, but you degrade some of the characteristics of the SS in the process. You could also make the padeye up from a SS middle pl, with two carbon steel side/cheek pls. to get the full width. This gets the carbon steel welding away from the frame or vessel.

 

[desertfox]

Hi

Does it have to be a welded lifting lug? Could you bolt or screw a lifting device on, which may be removed after installing,mas an alternative to what dhengr has suggested.

 

[StructuralNomad]

dhengr, desertfox,

Thanks for your replies. My first thought was to recommend Stainless steel padeyes as the frames were made of the same material. A proposal was put forward by the Contractor to weld Client supplied standardised padeyes with CS material.

Bolted connections are not allowed as per Client specifications.

Thanks and Regards

 

[kingnero]

It is possible, but it is not the best solution. The extra care necessary will likely cost more than the added expense of SS padeyes. What quantity are you talking?
I second dhengr's remarks. What if the padeyes are rusted away when you need them?

 

[dik]

I'd use stainless steel padeyes and passivate the welds with a nitric acid wash. The problems with the coating and welding of the mild steel will be a long term issue and if the environment is such that stainless is required...

Desertfox's idea of using a bolted connection has merit... and the padeye can actually be detached and stored away to be 'lost' <G>.

Dik

 

[StructuralNomad]

Thanks everyone for your valuable input.

Best Regards,