I'm evaluating the use of tank roof rafters made of S275JR steel (7 in total) as replacement for the original ones made of A36 steel.
There are some minor differences in dimensions (in millimeters), which I found negligible. However, the contractor suggested to use the same welding procedure...
There are some non-metallic alternatives that you could use until the next T&I, but then you will probably need to replace the plate as a permanent repair.