Heat treating problem

[Blacksmith village]

Hello.
As a beginner, I have now made some tools for the first time. Of course, that’s how I encountered tempering, and here is a problem. I used C45 steel which is basically 1045. I heated it to cherry red so the magnet didn’t stick anymore and quench in water. So far, I think everything was fine. Then I wanted to temper my slot punch. In the literature it is written that this is done at a temperature of 400-600 degrees Celsius. Which already seemed strange to me. I turned the oven to 260 degrees and left it for 1 hour. Now is colour of slot punch is bluish with some bronze spots. When I tested it with a file it cut almost like butter  What did I do wrong? still too high temperature? I know it should become bronze in color. Why then in the datashet it says 400-600 degrees Celsius?

 

 

 

[Latticino]

I tend to temper tools like that with the residual heat from the quench.  Only quench the first couple of inches with multiple quick dips in water (keep struck end hot, and soft).  Then quickly shine the working end with some sand paper or a broken grinding wheel and watch the colors run up to straw at the tip using the heat still left in the struck end.

You almost certainly tempered far too hot.  I don't have my heat treat app handy, but most common 10 series steels are tempered in the 400 - 600 deg. F range, not C,if I recall correctly.  Perhaps the guide you read was to temper it to a soft state?

[Goods]

Latticino, is stating exactly what I was thinking. For a struck tool like this you only want the working end hard. So, a residual heat tempering works great. One thing I will add to his description is to keep the punch moving rapidly up and down, about an inch. This helps prevent a insulating steam envelope from forming, and give a transition zone of hardness. (If you still have too much heat in the tool after you run the colors once, let them run again, don’t just quench it. You don’t want a hard spot in the middle of the tool and running to the same color a couple times may make the working end tougher.)

[Frosty]

400-600 is much too hot to temper. The method Latticino suggests is a proven way to control edge tempering on struck tools. Oven tempering is less suitable for struck tools if the struck end is hard it will work harden and may chip. Impact chipping steel is very dangerous.

Goods brings up an important issue using water, steam forms against the sides of the tool and insulates if from the water bath and prevents even quenching. These are bad things. I don't know anything about what products are available to you. In America we have household dish washing machines and a commonly available product to prevent spotting when they dry. One is "Jet dry" by name. It works by breaking surface tension where water on the dishes so water runs off without leaving droplets. A LITTLE Jet dry in the quench water does the same thing, it prevents water from sticking to the piece through "Cohesion." Steam as it forms floats to the top of the tank and condenses. 

There are other things that help, dish soap is one unfortunately it makes persistent bubbles and can be a problem. 

Salt is another but it also raises the  boiling temperature of water and provides a faster quench which may over harden steel. Water is already a fast quenchant, speeding it up isn't necessarily a good thing. However it should be just fine for 1045 steel, I can't say regarding C45. 

Make a couple test coupons before using it on one of your chisels or punches. No reason to do all that work for a test. Just forge a couple strips, say 3mm. thick and 25 to 30 mm. long. Test the heat treat temps and test to destruction. Keep notes.

Frosty The Lucky.

[swedefiddle]

Good Morning Blacksmith village,

You are on the right track. For cold work, only harden the tip (like what Latticino said) temper to a straw colour. Never harden the struck end (you will create a fault that can create tiny projectiles that will go through whatever you are wearing, or in someones eye).  For a slitting punch/drift for Hot Work, you don't need to harden and temper. When you use the drift in hot material, your tempering will be lost with the heat build-up, using 1045. H13 is made for hot working steel, it will not deform as easily. There is no problem using 1045 for limited production. 1045 and H-13 have completely different Heat Treating characteristics. H-13 is Air Hardening, 1045 is water hardening.

Neil

[Goods]

I should mention that chisel is very good work! Keep it up, and keep asking questions. We’ll help where we can.

If you are going the regarded it, I would recommend normalization is a couple times before you go for a quench. 

[George N. M.]

Dear BV,

The chisel is nicely done and finished as Goods says.  However, I have discovered that if making a chisel from round stock to carry the flats above the edge up the side of the shaft of the tool.  This makes it much easier to index the edge when you are using it because you have a tactile feel of how the edge is oriented.  If it is round and the light in the shop is not bright it is easy to have the line of the chisel off what you intend by a few degrees. I think that this is the reason that commercial chisels are usually made from hexagonal (6 sided) stock.

"By hammer and hand all arts do stand." 

[Blacksmith village]

I have watched quite a few videos about hardening and temoering in one heating but right now I thing is to much for my current skils (I am also colourblind slightly). It was definitely written in Celsius, but it could be really meant tempering to soft state.

#Frosty, now I have seen that the C45 is basically a 1045 but a European name. I really need to do test pieces. Here is an example of what school is and what practices are.

# Swedefiddle, what you said make sene to me. On hot steel hardening wil be lost. These tool I made for hot steel so can I leave it as it is now? 

#Goods, I was make normalisation. I put red hot steel in to ash to cool it slowly.

Sorry for my english. Google translate is my friend  

[Goods]

For filing and grinding before hardening, annealling in ash to get the steel to it’s max softness is idea, it may not be needed here. I was referring to just bring the steel to non magnetic then letting is air cool. others may jump in here and I would be curious myself. In this type of situation, what would be the best approach. With no forging to refine the grain structure, but wanting to completely redo the hardening of something, would a couple normalization cycles be best or a full anneal?

Thanks,

David

[David Kahn]

Another thing to keep in mind is that if you’re forging and heat treating in open air, some of the carbon in the outermost surface of your work can get sucked out of the steel and react with the oxygen in the air. This sort of surface decarburization will mean that the outer surface of the work won’t have enough carbon to harden and so the tool can seem soft to a file test until you file through the decarburized layer. 1045 doesn’t have that much carbon to begin with, and you could easily have a couple of thousands of surface decarb. You might try filing a bit to see if it’s hard (or harder) underneath.  
 

Btw, you didn’t say: did you file test the tool before you tempered it?

[anvil]

There is no one temper temperature. You temper or draw back the hardness for the work you are doing. For instance if you are making a wood chisel , depending on the steel, you want a straw color. If you are making a cold chisel for steel, you want a blue color. Sorry for your colorblindness. Check these colors on any good heat treat chart to get the proper Celsius or farenheit equivalences.

Also, 1045 is a medium carbon steel. It's considered a "tough" steel. Meaning it handles shock without mushrooming.  It's best use is for hammers and hot punches. It's not the best steel for cutting tools that needs a higher carbon steel to best hold an edge.

[Frosty]

Here's a thought about working around your color blindness. You might be able to match the steel to a color chart without needing to tell what the actual color is. A friend to double check your color judgments will not only help evaluate your estimations but help train your eye to the reality of what you perceive. 

Make sense?

Frosty The Lucky.

[Blacksmith village]

 

3 hours ago, David Kahn said:

 You might try filing a bit to see if it’s hard (or harder) underneath.  

Btw, you didn’t say: did you file test the tool before you tempered it?

Maybe I can try that too. I tried it right after hardening but the file didn’t "stick" like that. 

 

1 hour ago, anvil said:

Check these colors on any good heat treat chart to get the proper Celsius or farenheit equivalences.

Also, 1045 is a medium carbon steel. It's considered a "tough" steel. Meaning it handles shock without mushrooming.  It's best use is for hammers and hot punches. It's not the best steel for cutting tools that needs a higher carbon steel to best hold an edge.

This color I got is shown on the charts at about 300 degrees Celsius my oven was set to 260. Thankfully I don’t have complete color blindness, but hard to know the difference between some shades. I also have a hard time distinguishing when cherry red is here I help myself with a magnet. 

Off topic: What about 4140 steel? It is better for punches? I know it’s also medium carbon, but these two steels are steels that I can buy relatively easy. Everything else is rocket science. It would be easier to build a rocket than to buy another high carbon steel. I have some coil spring but it is only 12mm diameter. For example I want to make flint striker where I need 0,7 or better 1%C. Also rocket science. Only old files are an alternative.

 

1 hour ago, Frosty said:

Here's a thought about working around your color blindness. You might be able to match the steel to a color chart without needing to tell what the actual color is. A friend to double check your color judgments will not only help evaluate your estimations but help train your eye to the reality of what you perceive. 

Make sense?

Frosty, these make sense yes. I try to help myself in different ways as much as possible. So maybe I’m complicating things with the oven and trying to set the right temperature instead of doing it in one heat and watching the colors. A colour chart in hand and a comparison would make these easier.

[Frosty]

I believe you'll have much better luck learning to judge colors than relying on a chart that says to temper medium carbon steel to 300 C. 572f would run most of the hardness out. 180 c. - 230 c. would be much more in keeping with what I temper to. 

A file should skate on fully hardened steel but would still bite a little on hardened 1045.  You know what a filing steel feels like. Yes? That's "biting." Skating feels like the file is slipping on ice, no bite at all. Maybe like sliding a cup on a counter is a better comparison. File test after hardening, before tempering, it can save you time and work. If it didn't harden properly then tempering it isn't much use. 

You wouldn't put oil in an engine THEN look at the dip stick. 

Frosty The Lucky.

[arkie]

Frosty, if you are color blind or partially color blind, then trying to compare your work piece to a color chart will be frustrating, 'cause you won't be able to see the chart colors correctly either.  I am color deficient and have problems with the shades of reds/oranges and blues/purples.

[Blacksmith village]

Yes I know what a filing steel feels like. And I know what it's like to put oil on someone's file haha. A common practice at school. 
Next time I will try with lower temperature. This was my first attempt and I have to learn from my mistakes. 
 

4 hours ago, arkie said:

Frosty, if you are color blind or partially color blind, then trying to compare your work piece to a color chart will be frustrating, 'cause you won't be able to see the chart colors correctly either.  I am color deficient and have problems with the shades of reds/oranges and blues/purples.

That's it. I have exactly the same problem:  reds/oranges and blues/purples. 
Arkie how do you handle this? I think you already have some experience.

[Frosty]

4 hours ago, arkie said:

Frosty, if you are color blind or partially color blind, then trying to compare your work piece to a color chart will be frustrating, 'cause you won't be able to see the chart colors correctly either.  I am color deficient and have problems with the shades of reds/oranges and blues/purples.

No I don't mean look at a chart then look at the steel I mean direct comparison, hold it up in front of the chart. You don't have to tell one from another to match one against another. Our club printed up various temperature color, decimal to fraction, drill bit to tap, etc. charts and had them laminated. Nice charts once I convinced the guy having them done not to put ALL the charts on one page. 

My color vision is fading with age and probably looking at too many bright things, my red brown vision is off. I can see them fine just not what most folks see. So, after making the suggestion and thinking about it I took one of the color charts I'd printed during the selection process and went out to the shop to try it out. 

I was a lot more accurate with temper colors but boy was I surprised how off I was on critical I was estimating red, orange and low yellows pretty high. What looked like 1,800 f. was closer to 1,650 f. The steel being a Incandescent color looks brighter than the same color in ink, a reflected color. Putting one next to the other showed the color but looking at them individually the steel looked hotter than it was. 

I used to know this stuff, learned to use the differences between additive color vs subtractive colors, Lights vs. filters. They have different characteristics, especially on film. That and seeing it this morning leads me to believe it's a factor in judging hot steel. It is for me.

Now to hope I can just learn to compensate without having to hang a color chart to the wall.

Oh GOOD GRIEF!  It literally just now occurred to me, I don't know if our printer colors are accurate. Be really funny if my eyes are right and the printer is off. I'll have to call around the computer store or maybe a photography studio and see if I can find a calibrated color chart. Now I'm wondering what color the house really is.

Frosty The Lucky.

[anvil]

If you are colorblind, then use tempil sticks. They come in different heats and melt at that temp.

If your file bit after hardening, it wasn't hardened properly. 

You can use any steel you want including mild steel. It just will need to be dressed more often than if you use the correct steel for the job.

 

[pnut]

Doesn't salt become molten right around the critical temperature? 

Pnut

 

[Steve Sells]

depends on what salt you use

Edited June 8, 2020 by Mod34
Excessive quoting

[JHCC]

Table salt (sodium chloride, NaCl) melts at 1,474°F (801°C).

[arkie]

Frosty, I hear what you are saying about direct one-beside-the-other comparison.  That might be a better way to check the temper colors.

I found a long time ago, BEFORE my color deficiencies got even worse, that I could distinguish colored light much better than colored pigment.  I failed the Ishihara pigment test trying to get into the USAF navigator school, but when they gave me the light test, I did OK.  I have no problems telling a green traffic light from a red one, thank goodness!  Due to the red deficiency, I have trouble distinguishing greens and browns (red+green) in pigment unless there is less red in the mix, then I see the greens.  Same for blues and purples.  If the purple has a lot of red in it, I can usually see it as purple, otherwise it just looks like a darker shade of blue.  When I temper and have to distinguish blue from purple I just go with which ever I see first!! DUH.  I have no problem with the red-orange-yellow incandescent light in forging hot steel.

As for your printer, there is a big difference between printing on paper and photo paper.  My wife is an artist and if I print a photograph for her on paper, she says the colors are all off, but if I print on glossy photo paper, the colors come out almost perfect.  Monitor colors are usually pretty accurate if set to factory defaults.

 

[anvil]

Again, I recommend Tempil sticks. I can't post their addy so I suggest a Google search.

Here's a paraphrased summery from their website.

116 different sticks representing temps from 100f to 2000f.

They instantly melt at their temp giving a visual indication when your steel hits that temp.

They are like a pencil and you make a chalk like mark on your steel. When it melts,, well there you are. Easy to use and very accurate. 

They are prolly available on Amazon as well.

 

 

[Frosty]

Good point about the paper, I hadn't thought about that. I'll repeat the experiment with photo paper. 

I think my color perception showed in tests 2-3 years ago with a full blown test everything visit to my ophthalmologist. I've been seeing this office since the accident and nerve damage, my main ophthalmologist is a neurological eye specialist. I spend a lot of time in that chair while she shines a light and scopes things our while telling an assistant what's what. I haven't had "just" a checkup in a long time. My in depth checkups are crazy detailed photos of each eye with different cameras and put my face into at least 6 machines. 

I was surprised when I couldn't see the letters and numbers on the card. Funny thing is the deterioration is different for each eye. My left eye is more light sensitive too. Funny I need good light to see but too much and I get headaches starting in my left eye. I expected my eyes to change as I aged but man did that tree scramble things.

Frosty The Lucky.

[pnut]

12 hours ago, arkie said:

Monitor colors are usually pretty accurate if set to factory defaults

It's been almost ten years since I did any post processing for a paying customer but there was a pretty big problem with photographic prints coming out of the printer much darker than they would appear on the monitor at default settings. I'm glad the folks manufacturing the monitors have finally taken care of it. Back then you had to spend extra money on calibration programs and devices to fix it. I had to buy a product called spider color calibration suite and it set me back about four hundred dollars. 

Pnut