Question about heat treatment of castings
Question about heat treatment of castings
(OP)
I have a casting designated C35CrNiMo6.6. The parts made from these materials (relatively large block of 150x150x700 mm) show extreme poor mechanical properties, with yield and tensile almost equal, elongation <2% and Charpy-V values of average 7-8 J.
Can this material be heat treated (normalizing, followed by quench and teper perhaps) with negative effects such as grain-growth, or this is just "scrap"?
Can this material be heat treated (normalizing, followed by quench and teper perhaps) with negative effects such as grain-growth, or this is just "scrap"?





RE: Question about heat treatment of castings
Regards
RSVP
RE: Question about heat treatment of castings
Compostion should be
0.32-0.38%C
0.6-0.8%Mn
1.40-1.70%Cr
1.40-1.70%Ni
0.15-0.35%Mo
I haven't checked compostion (yet) but based on microstructure I assume carcon is ok (the rest i can't see obviously)
RE: Question about heat treatment of castings
Your dimensions of 150x150x 700mm is not too big. The weight of the block is just 126 kgs, too small for grain coarsening to happen ( for good foundry practice).
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: Question about heat treatment of castings
I am just interested to know if properties can be restored by proper heat treatment. That would save time with regards to repairs.
RE: Question about heat treatment of castings
Technically for a rough casting, free from Widmanstatten structure,one should be able to improve the properties by reheatreatment.
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: Question about heat treatment of castings
If the material is in the as-cast condition, then, yes, the properties can be improved with proper heat treatment. If those are the properties after heat treatment, then it would seem there was a problem with the casting or heat treatment, or both.
RE: Question about heat treatment of castings
Then, why not divide that block into more handy parts? With a block of that size, mech. properties in themthemselves will vary acc. to thickness.
If chem. composition of low alloy steel is correct, a lot can be done by retreating. However the heating technology for such block might be something for the knowledgeable / experienced company with resp. equipment. I'd seek input from s-one reputable.
Regards
RSVP
RE: Question about heat treatment of castings