welding of crane wheels

Date 03-06-2009 17:40

Anyone have some input on a welding procedure for crane wheels? I have a set of 4 crane wheels that our maintenance dept wants me to weld the OD of. They gave me results from a hardness test that varied from 35.9 Rc to 46.5 Rc on the outside and from 46 Rc to to 48 Rc on the "wear" area. (work-hardened?) Also they had a PMI test done however it only gave the results as C/S -readings were from 97.56% Fe to 97.68% Fe and Mn was listed as .56% to .97%. They want me to average the hardness and match that after welding and machining. I continue to argue that I need more information in order to develope a welding procedure. Am I being to hard headed and is there something that I am overlooking here? Can I really make an educated guess at what this material is and develope a procedure from the information that I have?

By ravi theCobra (**)

Date 03-06-2009 20:15

These crane wheels were probably ( ???????????????????????????? ) induction hardened after manufacture -

Can't you get replacements ? Any build up with say 8018 0r 9018 is doubtfull -

By Cactusthewelder (*****)

Date 03-06-2009 20:19

I have built upthe outside of some crane wheels for Brown and Root with a Hobart wire called "Frogalloy" It was designed to weld "Frogs" on a Railroad track. Brown and Root Engineers said this was the only alloy that would withstand the wear and tear. Hope this helps.

By DaveBoyer (*****)

Date 03-07-2009 05:14

At the auto frame plant they did weld up crane wheels, probably with an alloy like Cactus mentioned. I don't remember the details, I think they might have turned the worn surface down in the lathe first to allow an even deposit with some thickness to it. Seems to me someone mentioned that the weld tended to peel off over time. Those cranes lifted up to 20 tons. I think You want a filler alloy that is machinable as deposited but will work harden in use.

By uphill

Date 03-07-2009 12:19

We have used stoody 105-g with preheat on low alloy trolley wheels and crane idlers with good results. It seems to hold up to heavy rolling loads and welds consistantly. Multi-passes with 1/16 ran at 260-280 amps 25 volts with 98% Ar and 2% O2 shielding gas. Cant find the preheat temp.
Dave

By RonG

Date 03-07-2009 15:08

No you are not being hard headed. Some people do not understand what went in to building somethings in the first place let alone why welding could do more harm than good if cetrain requirments are not met.

I should think Safety is a big issue in this. I bet some body would be really upset if a wheel broke in two while carrying a heavy load, or if a piece of wheel fell on some ones head.

There's more to consider than just rebuilding the OD of the wheels. The hardness you gave sounds like commercially heat treated 4140 or 1040, most likely the latter. To bad a PMI can't read Carbon content.

I'm sure you know welding will created a HAZ that will be a lot harder. If you PWHT (stress relieve)(and you should) it you need know what the Tempering temp was used so you do not exceed it.

By alumtig (**)

Date 03-12-2009 13:02

Thanks for all of the responses recieved over the last week, I've been so busy that I have not been on the web site. I just got off of the phone with a welding engineer from one of my suppliers and he recommends a chemical anaylisis be done; as have others that I have spoken with. The PMI gives me a large % of iron, up to 98.51% and a small amount of Mn .80% which he tells me probably indicates a soft steel that was heat treated. I am trying to set up a meeting to come up with a resolution to this issue. New wheels would have been a great option but the owner was reluctant to spend the money. We have the capabilities to make "new" wheels as well and I would even recommend that avenue, however I'm having a difficult time convincing management that this is a little more than just smearing some weld on something and machining it. Will let you guys know the final outcome eventually.