welding gears to shafts..metallurgical

I need to weld a gear to a shaft(yet to be made) I do not know the type of steel that the gears are made from. I do know the hardness is 64Rc. Pretty hard. I was mainly concerned with the weldability if the gear is carburized and also, the loss of the HT in the gear post weld. The welding is near the teeth. If so, I would/can get the shaft with the gear re-heat treated. Then that leads to knowing the gear composition and then using the same filler so the HT is consistent. I talked to the HT place here and recieve no help. If I cant find out what the gear material is, I was thinking just to use a 4130 shaft and filler and just weld and try to heat treat. The guy at the HT place said we can try it. I dont think I have time to get the gear chemically tested, but thats an option... what do you suggest?

Need "PMI" for this sort of planning. There are inspection services with portable equipment that can come to your place to do a "postive material identification" (for a fee of course) and then you will know exactly what you have and whether what you plan is feasible.

John

Seems a bit odd to weld a gear to a shaft near the teeth, but the probability is high that the gear is 8620. OR, that's what the interior of the gear still is. It is probably carburized (case hardened) and then tempered at 300 deg. F.

How to end up with a good, undistorted gear will depend on how big the gear is and what it's used for.

I had little luck finding any companies that do PMI locally. I will post some pictures of the gears soon. thanks

This was on Yahoo Yellow Pages

Metallurgical Services Inc
Address: Orlando, FL 32803
Phone: (407) 898-0880

They may be able to help

John