Liquid Metal Embrittlement 1

[gieter]

We have problems with melting pots made of steel due to liquid metal embrittlement by lead and zinc.

The lead is poured in to the pot at very high temperature (900-1000°C!) and we have a great number of small cracks on the spot where the pouring stream hits the steel.

For the zinc we have problems in the blends of the pots.

Any suggestions?

 

[Metalguy]

The first thing that comes to mind on this is ceramics of one kind or another. Have you considered any?

 

[gieter]

We are considering it, but it's expensive. We would prefer a solution without extra costs (material change).

 

[hacksaw]

you can preheat, change how you fill them or bear the cost of making no changes(i.e. the cheapest solution).

 

[DSR]

The zinc die-casting industry has the same problem with their transfer pots. I've seen a thin ceramic wash used on steel pots to reduce the problem but as the ceramic wears away with time the pots have to be recoated or they crack

DSR

 

[Metallo]

What is the grade of the steel used for the steel and what is the composition of the lead?
The reason of this question is that we found that nickel free steel are much more resistant because if you have some antimony in your lead you form intermetallic at the interface.