Quench crack potential

[evan_z]

I am seeing some castings with quench cracks appearing in areas close to secondary shrink. Does anyone know if there have been studies into whether areas of secondary shrink would increase the potential for a quench crack?

 

[arunmrao]

Water quench or oil quench, carbon steel or low alloy steel, machined or rough castings, heavy or light section castings. Please provide more details, else most of the response will be a guess and it would do you no good.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[evan_z]

Carbon steel quenched in water. Section thickness is 2in. Rough castings.

 

[arunmrao]

Pl give the grade of steel and whether any normalizing was done prior to hardening.Did the cracks appear in the flame cut zone? How did the secondary shrinkage appear without machining?

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[evan_z]

It's an internal alloy that got normalized prior to hardening. The cracks appeared in MPI. There was only some grinding near the crack. Secondary shrink was found after opening the crack to investigate.