Metal Metal Heat Treating Experience

[opensourcefan]

I want to dive into the world of heat treating metals. I've never heat treated anything on purpose however I have worked with products made of all kinds of exotic metals capable of all sorts of crazy feats.

I would like to treat some basic steels and tool steels small small sizes and be able to test their hardness to see what I achieved. No knives or swords, just custom random tooling odds and ends.

I understand I will need some tooling, specifically tooling that won't burn the house down and or scare anyone at it's sight. Entering into this as economically as possible would be nice as I just want to play. If things get serious then I will upgrade as needed.

So... what do I need to get started in your guy's opinions?

 

[140mower]

I want to dive into the world of heat treating metals. I've never heat treated anything on purpose however I have worked with products made of all kinds of exotic metals capable of all sorts of crazy feats.

I would like to treat some basic steels and tool steels small small sizes and be able to test their hardness to see what I achieved. No knives or swords, just custom random tooling odds and ends.

I understand I will need some tooling, specifically tooling that won't burn the house down and or scare anyone at it's sight. Entering into this as economically as possible would be nice as I just want to play. If things get serious then I will upgrade as needed.

So... what do I need to get started in your guy's opinions?

Entry level...... A few fire bricks, a torch, magnet and a container of atf for dunking...... Beyond that, the sky is the limit.

 

[DPittman]

Well it depends on the size and type of metal you are wanting to heat treat and what heat treatment processes you want to do.

It can be as simple as a torch.

 

[opensourcefan]

MAP or will a simple propane into a make shift brick oven work?

 

[DPittman]

MAP or will a simple propane into a make shift brick oven work?

Possibly for small items. Straight propane doesn't get as hot as acetylene/oxygen torch.
Colour of the heated metal is often used as a guide to its temperature but in case you are not aware of there are temperature indicating crayons that can help with more precision.

Tempilstik 28050 Surface Temperature Indicator, One Indicator, 750 Degree F https://a.co/d/9VKCkxL

 

[thestelster]

Possibly for small items. Straight propane doesn't get as hot as acetylene/oxygen torch.
Colour of the heated metal is often used as a guide to its temperature but in case you are not aware of there are temperature indicating crayons that can help with more precision.

Tempilstik 28050 Surface Temperature Indicator, One Indicator, 750 Degree F https://a.co/d/9VKCkxL

The Tempilaq liquids only go up to 1500°F, but hardening 4140 and most other standard steels you need to reach 1525°F-1625°F. I think the stuff can be very usefull for tempering, though I've never personally used it.

 

[Mcgyver]

For me, 99% of the time its as Don says, couple of fire brick and propane/air. P/A is hot enough but as DPittman points it doesn't output as much heat as say oxyacetylene. I;ve just never really heat treated something that was super large at home. I've sent them out a couple of times, but just wasn't crazy about trying to heat, handle or quench 10 lb hunks of red hot steel in my confined and crowded garage. So the majority if mine have been smaller cutting tools out of O1, super common and easy to find at most industrial supply places.

Do you use insulated fire bricks. They are the super light ones you can cut with a saw, vs the heavy firebricks for a stove. The later soak up heat, the former do an amazing job of reflecting it back at the work.

Here's a cutter, irrc it start from 1" diameter O1. That and similar sized taps are about the largest I've done and the IFB & P/A has worked well

​

 

[trlvn]

MAP or will a simple propane into a make shift brick oven work?

Yes. Did this a few times with a buddy. We were making blades for a woodworking spoke shave. He drilled a hole through a fire brick just big enough to nestle the blank. We used two propane torches to heat to cherry red; only took a few minutes. The key was having the blank in a fairly confined space that concentrated the heat. Even just building a corner with fire bricks will prevent a lot of the heat from being wasted into open air.

Craig
(The same buddy got into blacksmithing and has a portable coal forge that he drags out from time to time. With that, we've inadvertently come close to melting steel!)

 

[DPittman]

The Tempilaq liquids only go up to 1500°F, but hardening 4140 and most other standard steels you need to reach 1525°F-1625°F. I think the stuff can be very usefull for tempering, though I've never personally used it.

I haven't used the liquids before but I have seen the sticks up to 1900°F . I believe I have one 1625° kicking around.

 

[thestelster]

I haven't used the liquids before but I have seen the sticks up to 1900°F . I believe I have one 1625° kicking around.

Huh! I'll have to check them out!

 

[DPittman]

Huh! I'll have to check them out!

Tempilstik Temperature Indicating Sticks

Markal Tempilstik Temperature Indicating Sticks Providing accuracy, confidence and compliance for over 80 years, Tempilstik is the original temperature-indicating stick with the best combination of precision and convenience for surface temperature measurement. Specially engineered for accurate...

canadaweldingsupply.ca

 

[gerritv]

You wuold do well to watch Marc's video series.

 

[opensourcefan]

Re Fire Bricks,

I suppose these CDN Tire ones wouldn't be the best since they're not insulated?

General PDP Template

www.canadiantire.ca

These are insulated though, just a little more expensive and requires shipping.

2500°F IFB Insulating Fire Bricks - 9" x 4.5" x 2.5"

Quality Lightweight IFB (Insulated Fire Bricks) 9" x 4.5" x 2.5" thick. Rated to 2500° F Fahrenheit that can be installed in either a backing or a hot-fired application. Easy to cut. If you need a higher temperature-rated insulating brick, see our 2800°F Insulating brick. The low iron content is...

canadianforge.com

I would like to have at least 4 to build a open sided box but maybe if I broke them all in half I could make up my heating chambers to suit the part size better.

 

[Mcgyver]

If you find a local retailer that caters to the pottery people, they should have IFB's and you'll save the the shipping.

I said "insulated", but properly they are "insulating". Those ones you found are the right stuff.

 

[trevj]

Re Fire Bricks,

I suppose these CDN Tire ones wouldn't be the best since they're not insulated?

General PDP Template

www.canadiantire.ca

These are insulated though, just a little more expensive and requires shipping.

2500°F IFB Insulating Fire Bricks - 9" x 4.5" x 2.5"

Quality Lightweight IFB (Insulated Fire Bricks) 9" x 4.5" x 2.5" thick. Rated to 2500° F Fahrenheit that can be installed in either a backing or a hot-fired application. Easy to cut. If you need a higher temperature-rated insulating brick, see our 2800°F Insulating brick. The low iron content is...

canadianforge.com

I would like to have at least 4 to build a open sided box but maybe if I broke them all in half I could make up my heating chambers to suit the part size better.

Skip the fireplace bricks. You'll spend half your effort (and heating energy) getting them up to temperature.

Well, maybe the better answer, is, "you can get better!"

The lightweight insulating bricks will not take the abuse that the fireplace stuff will, but it will also not absorb all the heat you produce. You can cut the lightweight bricks with a hand saw, if you want, or order some "Half-Splits", which are a brick split in half already.

If you are anywhere in or near a decent sized city, search for suppliers of Refractory Materials, and they should have castable, fiber, and firebrick available. I used Inproheat in Edmonton a lot when I was still out in the Prairies.
As said above, there will be a lot of the stuff available through Pottery supply outfits. Knifemaking supply places and Blacksmithing supply places are worth a look too.

Eventually, you will want an oven that you can control with a digital Controller. That way you can draw a temper to an actual know and reliable value, as well as doing annealing and artificial aging of aluminum alloys, and precipitation hardening of PH steels.

Do some reading, watch some videos. Plain High carbon steel is dead simple, some of the more exotic alloys are pretty complicated to heat treat.

Iron wire, and heat treating foil, can be your friends too!

 

[PeterT]

I found the lightweight insulating bricks at a local ceramic supplier. But they are so light, shipping should not be a killer from another city.