Im looking for some advise on welding 516-70 carbon steel to 410S stainless. i am welding a 5/16 and 3/16 plate with .035-309L HiSil with our Lincoln STT for a open root. Then proceeded to cap it with 309L flux core. The bend test failed on the face side (It split on the 410 side and followed the edge of the weld zone to the root). I have tried capping it with 309L rod but had the same if not worse results.