Welding manganese

By sweetjeep Date 12-10-2002 05:12

Help!
I've been working in a mining(rock-crusher) repair facility. We seem to be having trouble with weld repairs cracking out. These repair items are thick ,3" to 8" & thicker. Some cracking is radial, some circumferential. I'm guessing, I think we are told (by non welders) to preheat 500deg.F We pay no attention to interpass temps. or PWHT. Cooling is done at room temp. with Cer-Wool blankets. Any help would be appreciated. thanks Craig.

By GRoberts (***)

Date 12-10-2002 19:20

Is there any more information on the materials that you can provide? Is the matial acutally manganese, or an austenitic manganese steel? What weld consumables are you using?

By Niekie3 (***)

Date 12-10-2002 19:51

Hi Craig

I believe you are referring to austenitic managanese steel, also called Hadfield managanese steel? This material is typically used for crusher parts.

When welding this material, the big issue is to keep the heat input as low as possible, and to keep the interpass temperature as low as possible. This means NO pre-heat. Also, the cooling should be as fast as possible. This means NO blankets. In fact, if you are performing multi-pass welds, you may even cool the welding down using water as the component is rotated.

Another issue is the removal of the work-hardened surface layer before performing the repair welding. If you do not do this, you may experience spalling of the repaired surface once it goes into service again.

In other words, your typical repair procedure would be:

1) Remove damaged and work hardened material. (In the process, do not over-heat the material.)
2) Weld repair component using low heat input. (High speed GMAW & FCAW being a better process than SMAW.) Rather weld many small beads than a single large bead.
3) Ensure that the interpass temperature is as low as possible. Water cool if required.
4) Cool down following welding as rapidly as possible. - Can spray with water.

Hope this helps

Regards
Niekie Jooste

By sweetjeep Date 12-11-2002 04:52

Niekie3&GRoberts

Thank you both for Your time. Ive asked my foreman to get me the information on the material. As of now it seems we're doing everything wrong.

I've posted previously, How can one get information necessary to weld a given material. I've a little knowledge of metalurgy, still rookie level, searching for answers. Any info. to start looking would help. Does ASME,ASTM or other publish any books with such info. that someone(not a rocket scientist) could understand?

By Tim Buyle (**)

Date 12-12-2002 08:42

Don't forget the filler metals !!!

I agree with above procedure ... but what filler are you gonna use ?

My suggestion :

* worn surface : butter up with SS 307 type followed by surfacing with alloy type 13Mn or 13Mn4Cr3Ni
* crack repair : SS 312 type

Tim.