A well-known supplier of welded load ring, claims to supply an S355J2+N with impact test at -45. shouldn't he call it S355J4 / J5?
Can S355 reach these temperatures?
Reaching those temperatures (-45°C ?) isn't a problem. Achieving the impact values is or can be.
What are the impact values? What does he supply? Big difference between 27J and 100+ J.
I think the thickness of the welded load ring should be in the range of 10-15 mm.. The following table is useful to see the allowable thk. vs steel grades..