Ouch! Looking forward to the video of building a hand rail for steps. I've found that you don't bounce very well when you get old. Really glad you're still in one piece. No fooling about the fire hazard of quenching oil. Years ago in the shop they had parts that weighed over 30 pounds that were to be heat treated. Not having done parts that big before it was decided that since they couldn't agitate the parts in the oil they would agitate the oil in the 55 gallon barrel they used. They rolled some tubing into a ring and drilled holes in it and put it in the bottom of the barrel. The barrel was placed in front of the furnace, the work was pulled out and plunged into the barrel. So far, so good. Then... they turned on the air to the ring in the bottom of the barrel to agitate the oil. The fire was spectacular. Every time the air was cracked open the fire started again. The smoke was so dense it looked solid. After that they used Argon to agitate the oil. Cheers from NC/USA
A lot of people do not seem to understand that oil on the part dipped pulled out and let flash then put back in the forge you are actually putting carbon into the surface.... it's a good way to surface harden quickly and easily
Some 50 years ago, give or take, I watched a mill create castings for Steel Rolls, the giant rolling pins that are used to make plate sheet steel. These were essentially made with two grades of material, an alloy steel (lots of nickel) and "gray" iron (very low-carbon steel). The mold was filled with alloy steel, allowed to chill a specific amount of time, and then the grey iron was poured into it, filling the core and pushing the alloy steel in the center out. This method produced a somewhat flexible roll with a hard wear surface. Then it went to the machine shop, where it was turned on a giant lathe (this is a 40 ft. 40 ton piece of work) until it was round and of proper dimension. Heat treatment was not a part of this production process, swirling in a figure-8 would be rather difficult even for Ironman.
They only "grey iron" I know of is the common cast iron, which is a very high-carbon alloy. But it does produce white cast iron when quenched, a hard (but brittle) and wear-resistant material that would be just what one might want for the surface of a roller.
When making tongs we set the hot rivet and dip the tongs while continuously opening and closing them. You can feel the tongs get tighter with each dip. Once you reach the desired performance, let them air cool the rest of the way. If you dunk the tongs, the rivet will contract too much and they won't move.
In pilot jargon a good landing is one you can walk away from. I am glad that you are ok after that nasty fall. Thanks for the great information about types of steel and quenching.
Double dip can be so you can harden and temper in one heat. You harden the cutting edge by dipping, then plunge again when the edge has been warmed to temper temp by the un dipped section. Or so an old timer told me.
I have been watching blacksmith videos on youtube and they use carbon steel more often than iron, depending on what proyect they are working on, as they make a variety of things, from tools to decorative parts. It is very intereristing to see the matter from a machinist point of view. Thank you for the information and work you put on your videos. I hope you recover soon from that nasty fall :)
Thank you for such a nice explanation of why it is important to keep the part under the surface of oil until it has cooled. I had assumed that the only reason was to allow for thorough cooling of the part.
We do have white iron-very hard. If we tightly wrap the part in stainless tool wrap, can we quench it in the wrap? I’m talking about an 18 second quench oil, as that’s what I use? I just acquired tool wrap, but haven’t used it before. And what about A2 and D2 steel. I bought some A2 to experiment with, but the information on cooling that isn’t useful.
Careful with that flying Marc,. Keeping your nose down will keep your airspeed up, which will keep you from stalling, which will prevent bruised elbows.
At least you stayed in the battle and flew the aircraft all the way to the scene of the crash. However, I don't think you fully understood what we meant when we told you that you needed to "stick the landing." We DID NOT mean stuff the aircraft into the ground! Glad you're okay, Marc!
35 years ago I had a private pilot license and took a lesson a year ago, having an instructor to the right. 1) You probable didn't check up the "Equipment", Wheels (Shoes), wings etc. 2) Maybe the pre flight checklist was not done properly. 3) Checking the runway for obstacles is "very practical". Could it be fuel starvation that brought You down earlier then expected? Did try to take a short cut once but came to close to a solid table that flipped into a Roll, and a crash landing of course. A bone in the foot changed place but moved back with a large bang the next day…. It is dangerous to live.....
Heat treatment and sex have some things in common : They both make something hard and once you dip it in you never want to take it out ! Glad to see you didn't break your neck Marc! Maybe time for some sort of handrail on those steps ?
i think you are mixing up the pure chemical element iron FE with cast iron- cast iron has 2 to 6% carbon- wrought iron carbon level is below .04% - what is called pure iron has carbon content less than .02% - steel has from .10 to 1.5% carbon with other elements added
I don't buy this explanation of dipping that asserts that taking the work *out* of the heat sink allows the part to cool faster. It may be true that there's an enormous amount of heat in the phase change of a liquid into its vapour, but there's no differential diagnosis here: the liquid changes into its vapour just fine even when the part is submerged. You just don't *see* the wisps of cloud coming off the part, because they largely re-condense into liquid while still submerged with the part. The rate of cooling of the workpiece is determined strictly by its surface temperature, regardless whether it's in the Mariana trench, above or below the water surface in your quenching bucket, or in the vacuum outer space. With the "dip" method you're guaranteeing that the surface temperature is approximately exactly 100°C for much of the time, while if you dunked the part, the surface temperature would be *at most* 100°C, with slightly less control. I suspect rather the difference in method is just differing traditions that have evolved over decades or centuries. And an alternate hypothesis: the dipping method allows tempering to be achieved in one cycle. The initial quench achieves the (surface) hardening, then as the surface warms from the inside to some sensible temper a few seconds after the wisps of steam disappear, the blacksmith can terminate the cycle with a second quench.
