Could anyone offer a suggestion to an alternative material to ASME A105. Preferably a plate spec to one of the following standards BS, NES or DEF-STAN.
I believe that the most common complimenting material spec for carbon steel plate is A36, however, it fully depends on your design code and conditions for its use.
I suggest you ASTM 516 GR. 70 (see Table 1A from ASME B 16.5), however I'm agree with jmgee that the adequate material depends on your design code and conditions for its use.
a)19Mn5 according to DIN17155 (germany)
b)221-490 according to BS1503 (british)
c)AF48N according to M87-508 (french)
d) Fe510B according to UNI7746 (Italian)