tomwatson
Well-Known Member
Sorry to be a rock in the road, but all you think is happening with cold plates is not happening. I've been heat treating over 26 years with all types of metal and after several trips to college in Michigan on metallurgy, welding, and being a x-ray welder for 40 years, there is a lot for you to learn. In air hardened metals you get some benefit from plate quenching, maybe 1/2 to 1 point of hardness. I do it because it speeds up the quench over still air and allows me to get on with tempering. Plate quenching came about because machinists were having to make parts that were getting thinner and thinner. Plate quenching helped to keep the parts flat. Here are a few other things you don''t have to do.
1. Don't use a hammer to seal the seams if using SS tool wrap. A wood roller is made just for this. Closing the seams with a hammer can crack a seam inside where you don't see it.
2. You don't have to put a piece of paper in the bag to burn up the oxygen. Nor do you have to put a hole in the bag to do the same. You can ask the big heat treaters and they will tell you the same. When the oven begins to heat up, the foil being as thin as it is, absorbs the heat first and the O2 bonds with the 309 foil and becomes inert. This leaves the majority of the air in the bag as nitrogen which is a totally inert gas. The other gases left are very minor.
3. You do not have to put anything on the blades while they are inside the bag. If your blades are sticking to the bag, then you have had an overheat or you have been at holding temp with the wrong type of material.
4. You can quench the blades right in the bag using quench plates.
There are a lot of other things I could tell you, but I'm tired. Respond if you wish, but be nice to me.
1. Don't use a hammer to seal the seams if using SS tool wrap. A wood roller is made just for this. Closing the seams with a hammer can crack a seam inside where you don't see it.
2. You don't have to put a piece of paper in the bag to burn up the oxygen. Nor do you have to put a hole in the bag to do the same. You can ask the big heat treaters and they will tell you the same. When the oven begins to heat up, the foil being as thin as it is, absorbs the heat first and the O2 bonds with the 309 foil and becomes inert. This leaves the majority of the air in the bag as nitrogen which is a totally inert gas. The other gases left are very minor.
3. You do not have to put anything on the blades while they are inside the bag. If your blades are sticking to the bag, then you have had an overheat or you have been at holding temp with the wrong type of material.
4. You can quench the blades right in the bag using quench plates.
There are a lot of other things I could tell you, but I'm tired. Respond if you wish, but be nice to me.
Steel aging? That sounds intriguing - looking forward to it.