Stainless steel welded to A36 steel? 1

[macan1]

I have a horizontal stainless steel (SS) base plate with A36 vertical stiffeners.
The vertical stiffeners will be painted after welding with the SS base plate.
Can we weld SS steel to A36 steel?
Would the paint protect the welds from corrosion?

 

[metengr]

Could you identify the particular grade of stainless steel for your base plate? I would assume that it is a 3XX series, but I want to be sure so that you select the correct filler metal. There are various types of stainless steels - austenitic, martensitic and ferritic, which may require specific filler metals.

 

[macan1]

Dear metengr,
The stainless steel is grade 3xx
After welding, can we paint the A36 stiffeners and the welds?
Would the paint protect the welds from corrosion?

 

[metengr]

Could you describe the component and what environment the welded base plate and stiffeners will be exposed too? When it comes to joining dissimilar materials, the welding is straight forward (309 filler metal), and you really need to look at exposure to environment and the potential for galvanic corrosion.

 

[macan1]

Dear metengr,
Environment: pedestrian bridge, off-shore.
The base plates are suppoting beams for the bridge.
The bridge is located about 4m above sea water level.

 

[metengr]

Ok. I would select either a good quality exterior paint or epoxy coating, grit blast clean the surfaces and completely cover the A 36 stiffener plates and overlap on to the weld joint and the stainless base plate.