manganese

By Rick Hoople (*)

Date 04-08-2008 02:00

Have you tried to slow cool the piece? Wrap a heat blanket around it.

By Superflux (****)

Date 04-08-2008 05:19

Slowing the the cool down time is certainly a good idea in most scenarios. Used to weld on non magnetic manganese pivot pins (6" diameter). There was a shoulder on one end, so after installing the pin, we would have to make a donut or shoulder (mild steel) for the other side of the pin to keep it in place. I would use 350 F preheat, weld with 3/16" E310-15 SMAW and peen the weld for Stress relief. As this was usually during lunch break (repairing the crack from the previous shifts pin installation) neither of us had the time for the luxury of post weld heat treatment. Hurry up, weld it, git that machine digging again.. The peening seemed to work as I can't recall ever hearing of them failing after the second weld. Some thing else to consider is you might need to butter the weld zones (both the steel and the manganese) to get a dilution prior to making the final weld. Sooo..., I don't know if it was the additional weld or the peening.

By Fredspoppy (**)

Date 04-08-2008 11:20

Do you know the grade of the mild steel? From the "manganese" plate, I would guess that you are working on something in the crushing/abrasion workplace. If so, the mild steel may, in fact, be some type of abrasion resistant steel that would benefit from a fairly high preheat. Sounds like a cold cracking mechanism which is normally related to microstructure and the presence of hydrogen.

By welder77 (*)

Date 04-09-2008 00:30

The manganese plate is used as a runner for a clam dredge,which is towed on the bottom of the ocean to catch surf clams.Which in turn is used by the soup companies for chowder.
The mild steel the manganese plate is welded to is a piece of 10" shipwright channel.I arc gouged the old welds out and rewelded.I was told by the rod manufacturer to run the first
pass 80% to the mild steel side.Hopefully this will correct the problem. Thank you for your reply.

By 803056

Date 04-09-2008 05:08

I did a quick search for the electrode listed and found very little information. I'm not even sure that the electrode I found is the same as that being used in this inquiry. The Stulz Sickles website doesn't list the same electrode listed in the inquiry.

Based on what I did find, it may be the same electrode, it appears that the deposit is austenitic, which would explain why the weld doesn't crack. However, the high manganese and chrome could diffuse into the mushy zone of the HAZ on the carbon steel side of the joint. The increased alloy content in the mushy zone could result in martensite on the mild steel side of the joint. The hard martensite would be sensitive to diffusible hydrogen and result in delayed cracking if the electrode used is not of the low hydrogen type or if it is low hydrogen, it isn't properly stored in an electrode oven to prevent the absorption of moisture.

The delay in the occurrence of the cracks sounds like delay cold cracking that can be caused by hydrogen from any number of sources. So, it would be advisable to make sure there is no grease, paint, moisture, rust, or any other sources of hydrogen in or near the weld joint.

I would give strong consideration to preheating the carbon steel before welding to it and I would check with the manufacturer to see what the recommended storage conditions for the electrodes are. If they recommend storing the electrodes at temperature, I would definitely obtain an electrode oven. I would also observe any exposure limits recommended by the manufacturer.

Let us know what recommendations the manufacturer provides and whether you have success or additional problems.

Best regards - Al

By Jim12

Date 04-10-2008 12:54

I work at a mine that has manganese lips on the buckets and we weld using 309-L wire (dual shield), The one thing I didn't see in this post is inner pass heat which may not be an issue because of thickness of material. As far as inner pass temp we wouldn't allow it to get any hotter then 450 degrees farenhieght. We did peen our welds and preheat and as stated above usually no time for post heat. Also as stated above about rod condition, you mentioned that this was for dregging clams so how close are you to the coast as when I worked in calif close to the coast there is alot of moisture which could cause issues.

By welder77 (*)

Date 04-11-2008 01:07

I LIVE IN NJ AND RIGHT ON THE COAST.THE DREDGE IS BEING BUILT WITHIN A STONES THROW TO THE WATER.HOWEVER THE RODS WERE STILL SEALED IN THERE ORIGINAL CAN,AND WERE IN PERFECT CONDITION WHEN REMOVED.THE ROD MANUFACTUER SUGGESTED HOLDING THE FIRST PASS TO THE MILD STEEL SIDE.WE DID THIS,AND IT SEEMED TO SOLVED THE PROBLEM.TIME WILL TELL.
I WOULD LIKE TO THANK EVERYONE FOR THERE HELP.

By Rick Hoople (*)

Date 04-11-2008 05:35

I'm curently involved with some very large mining equipment that has Manganese racks welded to mild steel. We can't go above 450°F and we butter weld the mild steel with 309 LMo then we weld to the Manganese. Knock on wood, no cracks. So I think you are on the right track.

By welder77 (*)

Date 04-20-2008 00:57

I had my salemans do some research on the rods I was using.He got in touch with a engineer from Hobart & UTP and both claim I was using the wrong rods.They said the rods I was using were for
welding mangenese to manganese or a high alloy metals.The Hobart engineer reccomended using the Chrome/Mang rods.I ordered a can ,and I will keep you posted.

By J Hall

Date 04-27-2008 13:51

I agree with Jim 12. I use 309L for joining manganese to mild steel and have had excellent results