Question: How to Naturalize steel for engraving

[jimzim75]

No, I'll be doing that also. I have some experience in that direction.

 

[kcstott]

What I'm trying to naturalize in a rolling mold. This has a heavier cross section than a
gun part. Most gun part don't have heavy cross section, where as mine is nearly a
inch and half.

The light duty naturalizing process for gun part could be done at 500° F, I dought it would
make any impression on the rolling mold at all. So this means longer and higher temps.
To cut down on as much oxidation as possible. I'm going to wrap the part.

Next, I going to low ball the heating to 800° for the first try and see the results.
If it isn't soft enough to use carbides on then 1000° and up to 1200 if absolutely
necessary. I would prefer to simple leave the item longer at a lower temp.

This is a side project so I'm in no great rush to complete it. When I do, I'll pass on the
results.

Talk to ya later,
Jim

Jim
I'm a Machinist Tool and die maker and have been following this thread.
I'm going to play semantics here but the "proper" term is Normalizing. Which is not exactly the same as annealing but for all intent in what you need would end in nearly the same result.
Annealing removes all heat treat from the metal and reduces it's hardness to dead soft state. It is performed by taking the metal to it's critical temperature and holding it there (soaking) for 1 hour per inch of thickness with a two hour minimum soak time. and letting it cool to below 1000 degrees F slowly Usually 4 hours or longer depending on the size of the part. Then removed from the oven and cooled in free air.

Normalizing is a pre heat treating process that is used to put the steel in a uniform state to better accept further heat treating. It may or may not make the steel easier to machine. Normalizing startes out like annealing but is done at approximately 100 degrees higher then the upper limit of the critical temp. Then being allowed to cool in room temp air.
As you can see this would not anneal the steel much at all.

So in reality what you are trying to accomplish is a combination of annealing and stress relieving
Which is actually quite simple.
Place your part in a electrically fired oven (preferred as a gas fired furnace will introduce impurities in to the steel) set the temp at 1200 degrees F once the oven comes up to temp with part inside set a timer for two hours at a minimum and then one hour per inch. For a three inch thick part three hours total for a one inch part or thinner two hours total.
Then shut the oven off and leave the part inside to cool until room temp or less then 400 degrees F with the door closed.
This process takes about six hours to heat and over night to cool in a small furnace or kiln. larger furnaces will of course would take longer.
But it will produce a part the is dead soft and very stable (i.e. it will resist deformation due to machining)
This is what some call killed steel. Call it what you will. But the above process works and works very well. although if the part is not wrapped in foil it will build scale but that subject has been covered quite will already.

 

[davec2]

Jerry,

The titanium acts like an oxygen sponge - it absorbs a tremendous amount of oxygen at elevated temperatures. Thats why, if you're trying to weld it, the welding has to be done in an inert gas filled glove box.

Dave C

 

[jerrywh]

Dave c.
How many times can you use the same piece of titanium???

 

[davec2]

Jerry,

You can use a strip of Ti metal until it all turns to a white powder (titanium oxide - same stuff they use as a very opaque pigment in white paint.) When I use titanium to absorb oxygen, I use it as a powder, flake, or "sponge". It is available from chemical supply houses and pyrotechnic supply places (like Firefox). It is often used in fireworks and I use it in the rocket propulsion business to accentuate the output of pyrotechnic igniters. In the rocket propulsion world, I also use it as titanium tetrachloride (clear liquid) which is known in the special effects community as "liquid smoke". When exposed to air, the chlorine goes off very rapidly as HCl and the Titanium immediately forms titanium oxide with the O2 in the air and forms dense clouds of white smoke. (In high school, I put some in the central air conditioning system as a joke - another story !!) They used to use this stuff for sky writing.

Titanium, in the finely divided state (i.e. as a powder or flake) has a lot more surface area to absorb oxygen than sheet or foil. I have the Ti powder in a salt shaker and just sprinkle a little on the part before I wrap it in the stainless steel foil. I have also just loosely wrapped the part in very fine titanium wire. Both the powder and the wire I only use once and toss it with the removed foil.

Dave C

 

[jimzim75]

Thank you KC,
I suppose I'm showing my age being a baby boomer and we were all pretty natural
back in the day. It's nice to hear from someone that has actually done normalizing
that's close in size to what I'm trying to do.

Jewellers have been so wrapped up in casting everything that I really don't have
as much experience with fashioning large dies. It's spiked my interest. While the
maniacs aren't pounding at the door for jewellery. I do thing I've alway wanted to try.

Thanks,
Jim

 

[kcstott]

It could also be the local dialect too.
It's like any other industry we have our own language and it can and often does vary be location.

Our oven was only big enough for a chunk about 10"X10"X6" and most of the time we were working on stuff much smaller.

 

[jerrywh]

Thanks Dave, good tip/