The company I work for is considering using cooling tower water as quench rather than city water (current condition). The estimated annual savings is over $30,000. City water here is about 600 PPM salt, while the cooling tower will be controlled at 1200-1400 PPM.

 

How will this increase in salt effect the cooling rate of the quench? Will these low concentrations of salt make a difference? Scale on the bars? Etc.?

 

We are processing mainly 1045 steel bar. Typically we acheive around 60 Rc at the surface and 55 Rc @ 0.050" case depth, depending on the setup and requirement.

More salt will cause it to quench faster....

No effect on quenching efficiency at all, with 1000ppm.

Scale: I'd say little difference. Seawater makes a big difference, with 35,000ppm.

Do you quench in water after induction heating? I thought the surface was quenched by the underlying material, which stays cold with induction heating.

Do you quench in water after induction heating? I thought the surface was quenched by the underlying material, which stays cold with induction heating.

Good point. Skin effect and all that. With a good conductor and internal current produces a energising field that will induce a cancelling current. Sort of eddy currents cancelling eddy currents.

Edited October 5, 201312 yr by Delbert