Duplex steel production in induction furnaces

[materialpinar]

Dear all,

I have a question about Duplex steel(2205) production in induction furnaces. This is my master topic . The company I work for does not want to work with refined ingot, so we will work with 316 L.
Can I clean the furnaces with bottom-dipping argon?
is there anything I can measure the nitrogen in the mine?
where should I start working from ?
can anyone help step by step to create a chemical with 316 l?
thank you very much in advance.

 

[bobjustbob]

I don't know what you mean by "clean the furnace with bottom-dipping argon." Before we would melt a CD3MN heat, we would melt a heat of stainless (CF3M or similar) and make sure that the furnace cleans out well.

I don't know what you mean by "measure the nitrogen in the mine." You can measure nitrogen with a combustion nitrogen analyzer. We would use a LECO nitrogen/oxygen analyzer to check the melt.

Making a charge with 316L plate should be trivial if you know what raw material you have available. It is pretty simple to create a spreadsheet if you don't want to do it by hand.

Bob

 

[EdStainless]

The mass balance for the charge is simple algebra.
Build a spreadsheet to make life easier.
Set up look-up tables for each feed material.
The biggest tricks are making sure to keep the C low enough, and to add the right amount of N.
Melting a ferritic ahead of the duplex is a good idea.
Make sure that you have a clean very low C iron source.
We used to by scraps of 1002ELI that they deep draw appliance cases out of. It was never over 0.01% C.
And likewise, you will need ultra-low C Cr also. Std FeCr won't cut it.
And pure Mo.
And this is why we bought master alloy when we needed to melt 2205.
Getting a low C nitrogen source is a pain, it is usually nitrided LCFeCr.

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P.E. Metallurgy, consulting work welcomed

 

[bobjustbob]

Ed,
How do you add the nitrogen bearing Chrome? We would generally add it after the first check of the nitrogen, none typically in the charge. We would get the bath hotter than we would typically for a stainless and add it in. We would get lots of slag but generally good pickup. It worked that way so I didn't really question it.

Bob

 

[EdStainless]

We kept the temps low and then added nitrided low C ferro Cr.
It took us a few tries to get it right.
In the end we bought master alloy that had higher than std N in it.
That way we could blend about 35% revert in it and hit the right numbers.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[materialpinar]

Dear all thank you for your answers,

I am starting investigation this topic, after ı will start production. And ı will share duplex steel production steps