Ferro Manganese or Pure Manganese? 2

[mahadhatu]

Has any one done any studies or know references pointing to which form of manganese is more effective in de-oxidation of steel melts? (ferro Manganese or pure electrolytic manganese)


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There is always some thing better out there...
Mahadhatu

 

[arunmrao]

commercially for all grades of steels high carbon ferromanganese is used,for stainless steels,low carbon ferromanganese and for very low carbon grades or Ni alloys,manganese metal is added.


If you think education is expensive, try Ignorance.
- Andy McIntyre


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[EdStainless]

The carbon content (and melting temp) is a big part of those decisions. Of course right behind which cost less

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Plymouth Tube

 

[mahadhatu]

Thanks for your comments. I am more interested in the performance aspect of these alloys. Depending on the final desired carbon content of the alloy under consideration, we use either electrolytic manganese( almost no C) or standard ferro manganese. Alloys where we use the this low carbon electrolytic (flake) manganese seem to have more pronounced porosity and shrinkage porosity. That is why I am questioning its effectiveness.

Thanks,

--------------------------------------
There is always some thing better out there...
Mahadhatu

 

[arunmrao]

Lower carbon or no carbon grades will obviously pose problems. You need to consider,other strong deoxidisers and perhaps inert gas purging in the melt to reduce your gas porosity.


If you think education is expensive, try Ignorance.
- Andy McIntyre


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[EdStainless]

The pure metal has a higher melting point and does not go into solution as quickly. I am not surprised that it is less effective.

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Plymouth Tube

 

[mahadhatu]

Ed,

You make an excellent point!

Its funny how we overlook the obvious and focus on complicated scenarios when problem solving.

I will post my findings.

I appreciate your input.

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There is always some thing better out there...
Mahadhatu

 

[deadrange]

arunmrao (Materials) 19 Sep 09 21:36 wrote
Lower carbon or no carbon grades will obviously pose problems. You need to consider,other strong deoxidisers and perhaps inert gas purging in the melt to reduce your gas porosity.


Lower carbon steel grades 1006-1012 typically use medium carbon ferro manganese. At least they did at the two mills I worked at. LC manganese was too expensive, especially compared against the cost of FeSi and Al. And typically most steel mills do not use the Mn as the de-ox agent. It's efficiency is too low compared with Si and Al.

 

[arunmrao]

deadrange,

good point, agree. I know med carbon ferro manganese is used for low carbon grades having 0.06% and above. I had stainless steels(<0.03%C),alloy 20,hastealloys, and high Ni alloys on my mind,.
In these alloys,you need to go beyond FeSi and Al additions and cost of deoxidiser is not important


If you think education is expensive, try Ignorance.
- Andy McIntyre


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[mahadhatu]

Thanks for all your comments.

The alloys I am most concerned with are stainless steels such as CA6NM, 304, 316, CD4MCu etc and their respective L grades. That is the reason why we switched to Pure manganese.


--------------------------------------
There is always some thing better out there...
Mahadhatu

 

[arunmrao]

CA6NM,CF8,CF8M do not Mn metal additions.LCFeMn is adequate,check your melting practice and degassing practice.


If you think education is expensive, try Ignorance.
- Andy McIntyre


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