Welding on case-hardened rod

Date 01-26-2004 17:34

I am wandering how you intend to remove any Chrome.

What is the material? Are you joining 2 pieces? What was the case harding process?

By HAF Date 01-26-2004 17:55

I was going to remove chrome by taking a shallow cut with a lathe. The material is 10v45 that was induction hardened. I was wanting to weld a custom mount on the end.

By jwright650 (*****)

Date 01-27-2004 19:41

HAF,
I'm sorta confused, are the parts to be welded chrome plated?
John Wright

By jwright650 (*****)

Date 01-27-2004 19:46

If they are chrome plated, don't try welding until you are confident all the plating has been removed. It will most likely make you ill to breathe those fumes.
John Wright

By G.S.Crisi (****)

Date 01-27-2004 19:16

If the material is SAE 1045 steel (I suppose that the "v" in 10v45 was put by mistyping), then there's no chrome at all in it. 1045 is a carbon steel whose carbon content is 0.45 %, with up to 1% manganese and minimum amounts of sulfur, phosphorus and silicon.
If 0.45 % of carbon makes welding difficult, case hardening makes welding impossible. So, it's imperative that you remove the case hardened portion (or thickness) of the rod. Fortunately, the case hardend thickness is just a few tenths of a millimeter, so the rod diameter won't be compromised.
A word of warning. If you intend to remove it by machining it in a lathe, you must use a carbide (tungsten carbide actually) cutting tool. Rapid steel tools do nothing on case hardened steel. Better still would be to remove the case hardened portion by grinding.
Once you've removed the case hardened portion, you can weld your mount directly on the rod. Due to the fact of the 0.45 % carbon content, some precautions should be taken: preheat to 200°F, keep the interpass temperature constant, slow cooling by wrapping the weld and adjacent region with insulating material, electrode selection.
I can't suggest an electrode right now, I should look into my books. However, it shouldn't be very difficult for you to chose the right electrode if you make a quick search into the catalogs of reputable electrodes manufacturers.
Giovanni S. Crisi
Sao Paulo - Brazil

By billvanderhoof (****)

Date 01-29-2004 01:14

I'm not sure that this material is actually case hardened. To me case hardening involves diffusing some element (carbon or nitrogen usually) into the surface so that it becomes more hardenable than the underlying material. Welding would probably mix the case into the substrate thus destroying it. Induction hardening (mentioned in a later post) involves heating just the surface of the material (in what is basically a microwave) and then either letting it quench into the cold substrate or quenching by other means. The chemical composition of the part remains unchanged. Welding would alter the hardness in the area of the weld. When I looked up 1045 steel it was said to be suitable for induction hardening.

Now for pure guesses. This sounds like a hydraulic cylinder piston rod. Hard on the outside for wear resistance then chromed for more wear resistance. An attachment on the end won't care about the wear resistance so welding isn't out of the question although one would want to be careful about embrittlement in the area of the weld.

I leave recommendations on the actual process to others.
Bill