Increasing of the carbone content after solidification

[stanislasdz]

Hi guys,

A strange case !

Juste before cooling a steel casting part with 200 mm we measured the carbon content and the result is 0.14 % after the solidification we take a sample for the part and the result is : 0.19 % C.

I believe there is a segregation but it seems so big !!!

Any help is welcome

 

[TVP]

What is the chemical composition of the steel? What is the composition of the mold material?

 

[stanislasdz]

Most elements are :

C % = 0.10-0.15

Mn % = 1-1.5

The mold is in Alphaset (chemical sand)

 

[arunmrao]

There probably has been a carbon pickup from the mold and core materials as you have used an organic binder. The residence time of the thick section casting in the mold is long also it remains liquid for a longer time in the mold resulting in easy pickup of carbon.

" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke

 

[stanislasdz]

Hi araunmrao,

Here the evolution of the carbon and the aluminium contents

 

[arunmrao]

To what depth of the casting from the surface did you find carbon pickup? Will this layer not get removed during machining?

" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke

 

[stanislasdz]

To what depth of the casting from the surface did you find carbon pickup?

10 à 20 mm

Will this layer not get removed during machining ?

i guess NO !!

 

[arunmrao]

That is quite large. Can you please try to pour a similar section solid in CO2 sand mold. This will eliminate the issue of carbon pickup from mold material.

" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke