S355 comparisons.... 1

[deco0404]

Hi Guys,

Im doing a little metallurgical research here with a 1966 version of De Ferri Metallographia and just want to get a rough comparison of the grain structures of certain steels. Obviously S355 wasn't around then, so am hoping some of you slightly more mature guys can give me a hand here. I'm thinking an old BS50E or ST52.3 seems close....

Just to add a little spice, the actual grade I have is S355G10+M Z35.........and a bonus point if anyone can tell me what the G10 really means. From what I can make out it is a specific customer requirement, but what confuses me is that the spec says it is a customer requirement, but why would anyone request a specific grade, that is not specific. ie customer says refer to spec, spec says refer to customer.......................

regards

Declan

 

[ulyssess]

BS 4360 Grade 50E and DIN 17100 Grade St52-3 were not required to have a fine grain, but in most cases these grades were delivered with a fine grain.
S355G10 is a steel grade from EN 10225 (Weldable structural steels for fixed offshore structures). This grade shall have a fine grain.
In EN10225 there are 15 different grades for S355 with different requirements of chemical composition, mechanical properties and for different product forms (plates, sections). According EN 10027-1 table 1 they are distinguished by G1 to G15.
S355G10 exists only for plates. 2 different delivery conditions are allowed: +N (normalized) or +M (thermomechanically rolled).

 

[vthomidis]

...just to add to what ulyssess mentioned :

Z35 means that the plate has been tested as to the reduction of area in the thickness direction ( "z axis" ) and the result was
not higher than 35% ( if 3 tests effected ) or respectively 25% ( if 1 test effected )