×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Mold Binder decomposition and gaz defects in Steel Casting
2

Mold Binder decomposition and gaz defects in Steel Casting

Mold Binder decomposition and gaz defects in Steel Casting

(OP)
Hi guys !

If any one can give me some informations or links on the relationship betwen the mold binder decomposition and the gaz defects in steel casting.

Thanks in advance !

RE: Mold Binder decomposition and gaz defects in Steel Casting

This data you can obtain from the manufacturers who supply the resin binders. Please bear in mind that organic binders evolve more gas than inorganic binders.

Gas defect and hot tear are 2 common problems attributed to binders. The other important defect being sand wash from cores/molds.

(As an aside, do you have no senior experienced person in the foundry to gude you .His views will be more relevant than what you might get on the net.)

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

RE: Mold Binder decomposition and gaz defects in Steel Casting

SFSA has done an extensive research on the subject some years ago.

Try to get hold of research report 87: "Surface contamination of steel castings from furan and phenolic no-bake binders"

RE: Mold Binder decomposition and gaz defects in Steel Casting

(OP)
Thanks all

Arunmrao :

Tanks for your advice, but our internals expert in our foundry can not found the origin of the gaz porosity.

If i can summarize we use :

Steel casting
Alaphaset sand
Arc furnace melting
Low carbone steel
the porosity defects is not constant and somme times we have very good parts and in other times we find gaz in the end solidification part.

The question we ask, the porosity provied from melting (H,O,N) or from the binder and what are the best practise to avoid the porosity in this case.

I am surprised to read that the porosity problems in casting are obvious !!! the paper taht i read underline that is  complex to undersatnd and avoid the gaz porosity.

Here some links i found :
 
http://www.rastgar.com/rec/papers/Porosity%20in%20Castings.pdf
http://www.improve.it/metro/file.php?file=/1/Papers/Cast_Iron/99-206.pdf

RE: Mold Binder decomposition and gaz defects in Steel Casting

Gas porosity problems are caused by improper process controls in your facilty. You have mentioned that at times there are good castings ant at times not. Please check if it repeatedly happens with one team of workers and supervisors in the plant. Alternately please check if it happens with one type of casting or with all. Does it happen only during end pouring or throughout?

Do you frequently change the suppliers for the binders? How good is the mold coating? Is the mold properly torched before closing?

You mention about porosity at the end of castings? It means that the venting is not sufficient for the mold gases to be released . Provide some flow offs. Low carbon steel pouring is very tricky. Try and add some deoxidisers into the moltem metal while pouring into the molds.

I can go on endlessly without knowing the root cause. It was with this in mind I suggested you seek the assistance of a senior.

It is not an insurmountable problem and can be very easily solved at the shop floor without reading academic papers.

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

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources