Rock-Candy Fracture
Rock-Candy Fracture
(OP)
Who can give us some data about the steel casting defect called "Rock-Candy" Fracture.
Thanks !
Thanks !
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RE: Rock-Candy Fracture
Regards,
Cory
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RE: Rock-Candy Fracture
" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke
RE: Rock-Candy Fracture
Your post jogged my memory. Right out of the "Physical Metallurgy Handbook" by Sinha.
http://www.chipsbooks.com/physmet.htm
RE: Rock-Candy Fracture
RE: Rock-Candy Fracture
" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke
RE: Rock-Candy Fracture
I don't have my copy of the Physical Metallurgy Handbook with me today. The Handbook is an excellent resource book for metallurgical engineers, and is not too expensive. As also mentioned by CoryPad, I would investigate an on-line subscription service with ASM.
RE: Rock-Candy Fracture
I checked in the Physical Matallurgy Handbook by Sinha, and the aluminum nitride embrittlement that can result in the "rock candy" fracture appearance in castings. The minimum amount of AlN to cause intergranular fracture (aka rock candy appearance), in carbon steel is 0.002% and for alloy steels is 0.004%.
To reduce the susceptibility to this embrittlement;
Additions of Ti,Zr,B,S,Mo,Ni or Cu to the steel
Use of the lowest possible amount of nitrogen (0.005% or less), aluminum (0.015 to 0.030%)
Increased cooling rate after solidification
Faster cooling rate in the range of 2100-1290 deg F after solutionizing to control the amount and size of AlN.
RE: Rock-Candy Fracture
RE: Rock-Candy Fracture
Avoiding Aluminum Nitride Embrittlement in
Steel Castings for Valve Components
V-Rep 84-
By
William C. Banks,
Senior Metallurgical
Engineer
Materials Engineering
Department
Flow Control Division,
Rockwell International
First Published 1984
" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke
RE: Rock-Candy Fracture