Welding ductile iron and steel together

[Hercules28]

Dear all,

What's the best applied process to weld Ductile iron to steel?
(Pipes)

Herc

 

[metengr]

Use the SMAW process with Ni-Rod (high nickel) for filler metal.

Review the information below

http://www.ductile.org/didata/Section8/8intro.htm

 

[swall]

Second metengr's recomendation. At one of my former employers, we used NiRod 55 and 99 to MIG weld steel brackets to DI brake anchor plates to fabricate prototype parts. One can also stick weld using NiRod electrodes.

 

[MikeMet]

To add, you will need to preheat to a very high temperature even for ductile iron. Consider a 500-650 preheat. The best option is to not weld unless you absolutely have to. Look into mechanical methods for attachment to elminate the cracking issues that can easily arise when welding any type of cast iron.

 

[swall]

Actually, no. If you look at the tech data from the manfacturers of Ni-Rod you will find that preheat is generally not required.

 

[Hercules28]

Just to contribute to this thread. talked to some welders.

You can SMAW, TIG and MIG weld these with slightly different electrodes and different +/-.

They do recommend preheat and a thermal blanket to slow the cooling. The weld should have a crown.

Thanks for your replies.

 

[btrueblood]

Swall, can you give a link for that info? It's contrary to the "common wisdom" and the link metengr sent says preheat is generally a good thing, at least for some CE levels of the parent iron.

 

[swall]

btrueblood--I can't give you a link, but I can tell you that the info came from the Huntington Alloys brochure on Ni-Rod FC 55 wire. It probably is from the mid 1970's. "Preheat is usually not necessary for ductile iron but better wetting action (wider weld bead) can be obtained with the use of preheat". Now given that thought, I have typically added 450F preheat to DI weld repair jobs I have written procedures on. Preheat may not be necessary, but it does no harm.

 

[btrueblood]

Ok, thanks.