建议楼主看一下ASME Ⅸ中的QW-431:“The grouping (F-Number grouping of electrodes and welding rods) does not imply that base metals or filler metals within a group may be indiscriminately substituted for a metal that was used in the qualification test without consideration of the compatibility of the base and filler metals from the standpoint of metallurgical properties, postweld heat treatment design and service requirements, and mechanical properties.”
单从标准的角度,在“其它条件都不变”的情况下相同P-No.母材可以互代,但是可能还要考虑316与304母材之间的差异,特别是耐蚀性能方面的差别。