WELDING CAST STEEL 2

[mistermusso]

I have a cast steel end shield from an electric motor that is cracked in 3 places.It is only about 10mm thick and every time I weld it the weld cracks.I am using 680s electrodes as this is all we have.Any comments or hints would be great.
Graham

 

[metengr]

Yes, find out if this is a cast iron or cast steel. Send a piece out for chemical analysis. I suspect it might be cast iron.

 

[mistermusso]

Unfortunatly I dont have time to send away samples I need to weld it quickly

 

[metengr]

Try one of the high nickel weld electrodes (Ni Rod 55 or 99). You can try to use a Metal Stitch repair, this is a mechanical fix using Invar dog bone stitches to restore structural integrity.

 

[deanc]

I would also suggest a preheat,perhaps interbead peening and a slow cool down if you weld.

You could also brass braze.

Have you called any local Job/Welding shops?

 

[arto]

Maybe do a spark test with a grinding speel to see what you've got? (used to be a chart in Grampa's old Ryerson Data Book)

 

[arunmrao]

Perform a ring test to identify if it is steel or cast iron. however, if it is DI then the situation gets confused.

Use the high Ni rods as suggested earlier by members to avoid cracking.

 

[DrRTU]

As metengr said, if the shield is cast, you may want to use these guys.

http://www.r-f.com/

Not cheap, but can save tons of lead time on a new casting. Welding builds in stresses and the material will slip at the end of the heat effected zone.

 

[dik]

You can try the following:

WELDING CAST IRON AND MILD STEEL

GRIND EXIST MATERIAL AS REQD TO PROVIDE CLEAN SURFACE AND PREHEAT BOTH WELDING SURFACES TO 400F.

WELD SURFACES USING METAL INERT GAS PROCESS. WELDING ELECTRODE TO BE AWS CLASS ENI-CI HAVING A MINIMUM 55% NICKEL CONTENT

COVER ASSEMBLY WITH INSULATION TO RETARD COOLING.

AFTER ASSEMBLY HAS COOLED, PREHEAT TO 400F AND COVER WITH INSULATION TO RETARD COOLING.

GRIND SMOOTH, POLISH AND BUFF

Dik

 

[0707]

Go to

http://www.welding-advisers.com/Welding-cast-iron.html

http://www.twi.co.uk/j32k/protected/band_3/jk25.html

If your stuff is white cast iron it is not weld able.

Dik has given good advice

Cheers

Luis

 

[dik]

0707: Excellent links, thanks, Dik