Need some help with identifying material ( cast steel or ductile iron)

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Howdy gang. I had someone contact me about repairing an old John Deere backhoe(mid 60's).  On the hoe, the end of the dipper arm, there is a cast piece welded to the arm. He broke one of the ears off. asked if I could repair it. He sent me a picture of the damage. It is a cast piece. Where it broke is shiny. I dont have any experience welding cast that heavy. I've only repaired thin stuff. But, in my limited experience, it looks like ductile iron. I did a drill test, and it gives off little chips, not like cast iron. I also did a center punch test( shown in the red circle) it left a bur. How would you repair this?



I looked up the number shown in the picture, but no luck. Nothing came back on google. Would me best bet be to preheat and weld with 309L?
Reply:Posting more pictures showing the broken parts, how they fit together and particularly how they attach to and function with surrounding parts would be quite useful. If, as you say,  the the end of the broken part was welded to another, also showing the (cleaned) weld area might give information about its weldability.What caused it to break; gross overloading, failure of something related, or 'unknown' conditions?The cited number probably refers to the casting and was used by the foundry, plus maybe the manufacturer's parts manual. Depending on age, it may be unknown to most searches..Last edited by Oldiron2; 12 Hours Ago at 02:53 PM.
Reply:Thanks for the reply. I am going back later to take the bucket off the arm. This piece is a cast piece welded to the end of the arm. I will get more pics, and come back.You can tell the piece has been broke for a while( the dark rusted art next to shiny part) it is the bucket cylinder link(?) He lost the pin retaining bolt, and the pin worked out of one of the links, putting all the cylinder force on the one side.Last edited by RCcrawler; 12 Hours Ago at 03:09 PM.
Reply:From the 60's, more than likely cast steel. Especially if its welded to a steel arm. Some preheat and 7018 will handle that.
Reply:...That's what I was thinking...But I did a drill test( have you seen FireballTool's video on identifying ductile or grey iron?) It gave off little chips. Not like what you would expect from steel. Would the cast steel do that? I told him I could do it with 7018 or dual shield if it wasn't cast.
Reply:

Originally Posted by RCcrawler

...That's what I was thinking...But I did a drill test( have you seen FireballTool's video on identifying ductile or grey iron?) It gave off little chips. Not like what you would expect from steel. Would the cast steel do that? I told him I could do it with 7018 or dual shield if it wasn't cast.
Reply:Even if it is cast steel, it may have enough carbon to cause problems with welding.  Do a weld test first.  Weld a short bead in an area that wont cause problems and let it cool.  Then hit it with a file to see if the bead has picked enough carbon to form hard iron carbide.  Next chip it off with a hammer and chisel.  If it cracks off under the bead, you are going to have problems.