HuFlungDung
Diamond
- Joined
- Jan 19, 2005
- Location
- Canada
So I'm trying to make these small steel bushings that are tapered inside. They are 3/4"OD, 10mm ID by .625" long, pretty small.
These are an extrusion nozzle for cold pressing seeds of various kinds, from an oil expeller.
I made an initial set from W1, and of course, the customer is looking for longer life nozzles.
Thought I would try A2 drill rod.
Problem I'm having is that I am doing the heat treat 'on the bench' with a flamex torch. I'm guessing at the heat, but am going well past the orange color I would use for a W1. I cool the part with an air blast. Distortion is minimal. But, the parts don't seem 'file hard' like W1 would be (in a water quench). I try to keep the torch on it the whole duration to minimize exposure to oxygen. I would expect a similar amount of decarb as I would in treating W1 which exhibits very little, if any, soft skin.
My question, which I can't really seem to find an answer to, is this: does the crystal transformation take place instantly upon reaching the 1900 degree temperature, or does it truly take a few minutes at a soaking temperature? I can probably have the whole operation done in a couple of minutes per nozzle, I'm just wondering if the material has not really transformed in that short of a time interval, hence the hardening is diminished?
These are an extrusion nozzle for cold pressing seeds of various kinds, from an oil expeller.
I made an initial set from W1, and of course, the customer is looking for longer life nozzles.
Thought I would try A2 drill rod.
Problem I'm having is that I am doing the heat treat 'on the bench' with a flamex torch. I'm guessing at the heat, but am going well past the orange color I would use for a W1. I cool the part with an air blast. Distortion is minimal. But, the parts don't seem 'file hard' like W1 would be (in a water quench). I try to keep the torch on it the whole duration to minimize exposure to oxygen. I would expect a similar amount of decarb as I would in treating W1 which exhibits very little, if any, soft skin.
My question, which I can't really seem to find an answer to, is this: does the crystal transformation take place instantly upon reaching the 1900 degree temperature, or does it truly take a few minutes at a soaking temperature? I can probably have the whole operation done in a couple of minutes per nozzle, I'm just wondering if the material has not really transformed in that short of a time interval, hence the hardening is diminished?