Hardening steel

[Spark plug]

im makeing some forgeing dies to go in my fly press:

I've made them from some old rail track witch from my reasearch I'm guessing is about 0.4-0.5% carbon.

Looking at the carbon content I've compared it to en45 Spring steel and found this information on hardening and tempering it:

Hardening

Heat the steel slowly to 650-700°C and thoroughly soak. Continue heating the steel to the final hardening temperature of 870-930°C and allow the component to be heated through. Quench in oil.

Tempering

Temper the EN45 spring steel immediately after quenching whilst tools are still hand warm. Re-heat to the tempering temperature then soak for one hour per 25 millimetre of total thickness (2 hours minimum) Cool in air. For most applications tempering will be between 400-550°C.

Does this sound about right or not?

I can get hold of a gas forge for the job witch should be easier than trying to do it in the coal forge but 2-3 hours to temper is going to be a lot of gas.

Any thorts?

 

[hotrodder]

Probably found this when researching rail materials but http://www.iorw.org/members/jobknow4.html lists the composition of several flavours. Like you say not too disimilar to http://www.westyorkssteel.com/spring-steel/en45/ with regards to carbon, bit more Mn and a fair bit less Si

I'd pay more attention to someone like TechnicAl than me but i'd say if you quench them don't skimp on tempering for the sake of a few quid on gas... you don't want bits breaking off and flying this way or that due to temper embrittlement either due to the wrong temps or not enough soak time for the part to heat through thoroughly... not the lightest of reads but about how certain temps can reduce impact toughness a chunk http://steel.keytometals.com/articles/art102.htm Note what the article says about silicon preventing/reducing embrittlement

For a fly press i would've thought a chunk of rail that's just been ground to shape would be good to go? Chunks of used rail certainly stand up well enough as is when hammering sheet metal on them by hand

 

[MattF]

For a fly press i would've thought a chunk of rail that's just been ground to shape would be good to go? Chunks of used rail certainly stand up well enough as is when hammering sheet metal on them by hand

I'd have thought they would be fine as is too. From what I've heard, the stuff ain't exactly soft.

 

[Bill Edwards]

Yes that procedure doesn't sound too bad. The common approach which I believe is best for the majority of steel is to heat until red (it is possible to overdo the heating, don't go mad) and hold it for some time. A rule of thumb is one hour per inch of material.
Then quench, on a piece like that I would probably opt for oil over water, but can't say for sure on such thicknesses. If swirling round change direction to the part is cooled evenly, a constant motion will give uneven cooling.
Then to temper is done by heating the metal slowly to the required temperature, probably around 280 C if using an oven or to a blue/purple if doing it by eye for a die - don't do it too hard and have it break with the impacts. Then cooling from tempering can normally be done by quenching or just leaving it, normally the method of cooling has no effect - some people quench to prevent the temper going too far, but on a piece like this the heat needs to be very, very gradual anyway to ensure it soaks right through.

I'm sort of agreeing with the others though, it's probably already hard enough to do the job unless it's been got very hot from heating/welding and lost its temper.

 

[Spark plug]

It's not as hard as you may think. It is certainly tough but it machined quite easily once the technique was right.

 

[MattF]

It's not as hard as you may think. It is certainly tough but it machined quite easily once the technique was right.

More details of methods, just incase anyone wants to go down the same route in the future.

 

[Spark plug]

I found the same for both turning and milling, slow spindle speeds high feed rate and big cuts. If you try to go to easy it will just work harden instantly. Oh and as mutch coolant as you can throw at it.

 

[Richard.]

Main line is usually carbon manganese type rail where as crossings are more often austenite manganese.

 

[TechnicAl]

To be certain you really need to know the composition of the steel. Rails can be a number of different grades. I believe we only use one grade on our Railway system but there are thousands of uses inside factories, steel works, mines, trams etc etc. These end up in scrap yards and people assume they are all the same. The composition can vary quite a lot. Carbon from 0.4 to 0.8% for example.

As Richard said sometimes even 14% Mn is used. Heat treat that in the way you mention and it will just fall apart.

 

[Spark plug]

This is starting to sound more complex than first thort.

 

[Richard.]

This is starting to sound more complex than first thort.

Why. I personally would just use the rail section as it is for your job. No need to temper or quench they are fairly hard in there worked state.

 

[Wedg1e]

I'd use an electric muffle furnace, but that's just 'cos we have one at work
Set temp, set time, do some work, come back when the red light's gone out.

 

[TechnicAl]

This is starting to sound more complex than first thort.

I didnt mean to make it sound complex. Its just that to be sure you need hard facts. Thats where Ive been all my life so I like to be sure.

Im not sure of the dimensions either........they look big chunks but that might be the picture

Have you got a little piece you could try

The question is that if it isnt the 50 carbon rail you think would that treatment cause problems to another grade. Thinking about it, the answer is probably no. If its higher carbon and heavy section the quenching could crack it but its probably worth the risk.

Im thinking out loud

Could you get a hardness test done? Its a simple and cheap test

 

[hotrodder]

What sort of work are you gonna be doing with the dies? Production runs or occasional use? Chunks of rail are used 'as is' for makeshift/poormans anvils and tinmans stakes/dollies all the time and stand up pretty well. Obviously if you want to make hole punches it's a different story but FWIW many of my home made sheet metal pressing, hole flaring dies and dollies are made from aluminium because i had some free maching ally to hand and it's sooooo easy and fast to machine. Obviously they won't last as long but provided they're not used several times a day they survive well
I'm not about to try but i reckon if i attacked a corner of my chunk of rail with a hammer the face of the hammer would suffer at least as much although obviously i could have a different flavour of rail

If you didn't have any problems machining it i would've thought it's fairly unlikely you have AMS (austenitic manganese steel)? New it's apparently relatively soft but gets 'kin hard 'kin quickly with trains running on it

 

[TechnicAl]

What sort of work are you gonna be doing with the dies? Production runs or occasional use? Chunks of rail are used 'as is' for makeshift/poormans anvils and tinmans stakes/dollies all the time and stand up pretty well. Obviously if you want to make hole punches it's a different story but FWIW many of my home made sheet metal pressing, hole flaring dies and dollies are made from aluminium because i had some free maching ally to hand and it's sooooo easy and fast to machine. Obviously they won't last as long but provided they're not used several times a day they survive well
I'm not about to try but i reckon if i attacked a corner of my chunk of rail with a hammer the face of the hammer would suffer at least as much although obviously i could have a different flavour of rail

If you didn't have any problems machining it i would've thought it's fairly unlikely you have AMS (austenitic manganese steel)? New it's apparently relatively soft but gets 'kin hard 'kin quickly with trains running on it

Good point

 

[Spark plug]

I didnt mean to make it sound complex. Its just that to be sure you need hard facts. Thats where Ive been all my life so I like to be sure.

Im not sure of the dimensions either........they look big chunks but that might be the picture

Have you got a little piece you could try

The question is that if it isnt the 50 carbon rail you think would that treatment cause problems to another grade. Thinking about it, the answer is probably no. If its higher carbon and heavy section the quenching could crack it but its probably worth the risk.

Im thinking out loud

Could you get a hardness test done? Its a simple and cheap test

The prices 4" wide, I forgot the mug. Yeah I have some offcuts I could play with, I can get a hardness test done if I can find some ware local. How should I harden the test pice?

 

[Spark plug]

What sort of work are you gonna be doing with the dies? Production runs or occasional use? Chunks of rail are used 'as is' for makeshift/poormans anvils and tinmans stakes/dollies all the time and stand up pretty well. Obviously if you want to make hole punches it's a different story but FWIW many of my home made sheet metal pressing, hole flaring dies and dollies are made from aluminium because i had some free maching ally to hand and it's sooooo easy and fast to machine. Obviously they won't last as long but provided they're not used several times a day they survive well
I'm not about to try but i reckon if i attacked a corner of my chunk of rail with a hammer the face of the hammer would suffer at least as much although obviously i could have a different flavour of rail

If you didn't have any problems machining it i would've thought it's fairly unlikely you have AMS (austenitic manganese steel)? New it's apparently relatively soft but gets 'kin hard 'kin quickly with trains running on it

This set of dies will be for drawing steel down and as such I need to maintain the smoth radius that's been machine to the top. They won't be used every day but they could see some high point loads especially if forgoing other high carbon steels.

 

[Richard.]

What sort of work are you gonna be doing with the dies? Production runs or occasional use? Chunks of rail are used 'as is' for makeshift/poormans anvils and tinmans stakes/dollies all the time and stand up pretty well. Obviously if you want to make hole punches it's a different story but FWIW many of my home made sheet metal pressing, hole flaring dies and dollies are made from aluminium because i had some free maching ally to hand and it's sooooo easy and fast to machine. Obviously they won't last as long but provided they're not used several times a day they survive well
I'm not about to try but i reckon if i attacked a corner of my chunk of rail with a hammer the face of the hammer would suffer at least as much although obviously i could have a different flavour of rail

If you didn't have any problems machining it i would've thought it's fairly unlikely you have AMS (austenitic manganese steel)? New it's apparently relatively soft but gets 'kin hard 'kin quickly with trains running on it

Yeah that's spot on. I've seen the crossings been manufactured and they machine really easily to profile straight after they are cast but as you say once a few wheels have rolled over them in service they become very hard and as Al said wouldn't cope well exposed to those high temps.

 

[Spark plug]

Looking at similar commercially available dies they are hardened to 52-54 Rockwell C. I'm not sure how this compares to say a hammer face or a punch die.

 

[desmo11225]

Hi Spark Plug
You say you've made your blocks from old railway stock, rails are made from manganese steel / Hadfield steel designed to work harden when put into use, we used to be told it only needed one train to pass over new rails and it would work harden, read Wikipedia Re Manganese Steel / Hadfield Steel You may find there is no need for hardening and tempering, it'll harden itself with usage. All the Best Good Luck desmo11225