- Joined
- Nov 16, 2012
- Messages
- 5,596
Well... how fortuitous that you ask...
Quenchant: For now, using baking soda and water. You must use what's correct for the metal. 1045 likes water cooling. What the books say about sinking potato peels -that's just a starting point. I test the solution by heating (with oxy/propane torch, simple mapp or propane torch is not hot enough) a 1/4" thick piece of metal until it's red/orange (color is important. Cherry red is cold. Orange, now you're talking) and dunking it until it does not boil with big bubbles but rather, fine "soda" or "carbinated water" bubbles. If the bubbles are too big, the hardness just won't be there in the finished piece. Add bi-carb soda until the desired bubbles are obtained when quenching a test part. Why bi-carb? It's a salt and it's cheap.
The water should start-out room temperature and there should be sufficient volume so the terminal temperature of the part and water is 150 degrees. I'm in the process now of writing the formulas to know how much water to start with to accomplish this. BTW: The books don't tell you this but it's easy inference if you see the picture of what's going on. At the very least, start-out with enough water and pull the part when it hits 150 (which is right at the threshold of being able to handle by hand). A rapid and smooth transition to 150 is the key. These little subtle points are what make a difference between something that comes out 30 RC when you intended 40 etc.
Pack Carburizing for low and mid carbon steel: So far, 95% crushed charcoal and 5% (by weight) potassium nitrate. Ground-up and crushed together. (Don't add any sulfur unless you plan to make gunpowder). I'm still tweaking this and may up the potassium to 10%. The potassium becomes solute with the charcoal at/around 500. The combination of the two produce a large amount of CO2 when temps hit 1300. This carries the carbon right into the metal as it starts to hit austentizing state. Of course, I'm wrapping in tool foil. The aftermath is not messy at all. Just some grey powder and scale afterward. It's all incenerated and the carbon is gone into the metal.
Ray
Quenchant: For now, using baking soda and water. You must use what's correct for the metal. 1045 likes water cooling. What the books say about sinking potato peels -that's just a starting point. I test the solution by heating (with oxy/propane torch, simple mapp or propane torch is not hot enough) a 1/4" thick piece of metal until it's red/orange (color is important. Cherry red is cold. Orange, now you're talking) and dunking it until it does not boil with big bubbles but rather, fine "soda" or "carbinated water" bubbles. If the bubbles are too big, the hardness just won't be there in the finished piece. Add bi-carb soda until the desired bubbles are obtained when quenching a test part. Why bi-carb? It's a salt and it's cheap.
The water should start-out room temperature and there should be sufficient volume so the terminal temperature of the part and water is 150 degrees. I'm in the process now of writing the formulas to know how much water to start with to accomplish this. BTW: The books don't tell you this but it's easy inference if you see the picture of what's going on. At the very least, start-out with enough water and pull the part when it hits 150 (which is right at the threshold of being able to handle by hand). A rapid and smooth transition to 150 is the key. These little subtle points are what make a difference between something that comes out 30 RC when you intended 40 etc.
Pack Carburizing for low and mid carbon steel: So far, 95% crushed charcoal and 5% (by weight) potassium nitrate. Ground-up and crushed together. (Don't add any sulfur unless you plan to make gunpowder). I'm still tweaking this and may up the potassium to 10%. The potassium becomes solute with the charcoal at/around 500. The combination of the two produce a large amount of CO2 when temps hit 1300. This carries the carbon right into the metal as it starts to hit austentizing state. Of course, I'm wrapping in tool foil. The aftermath is not messy at all. Just some grey powder and scale afterward. It's all incenerated and the carbon is gone into the metal.
Ray
Hey Ray, tell us about the quenchant and what you concocted for pack carburizing.