4140 surface hardening 3

[MetallurgistA]

hi, dear all, i read all your conversation about 4140 steel heat treatment and properties.
here i have a question. it would be appreciated, if somebody answers that?
i have a mold made out of 4140 fr shell sand molding but i want to harden its surface. can you please give me the exact cycle properties such as time for me ?????
o know the temperature 845-830 for austeniting.

thanks

 

[EdStainless]

i this a solid piece of material?
Could it be re-heat treated without distortion or cracking being an issue?
How hard is it now?

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P.E. Metallurgy, Plymouth Tube

 

[MetallurgistA]

at the first, thanks for your response.
this material (4140) is used as die in which shell sands are shoot to produce core. so, the sand particles erode the die's wall. accordingly, i want to make the die's surface as wear-resistant. to do so,I think i should use carbonizing to harden the die's surface.
is it good treatment?
help me please.
best

 

[arunmrao]

For shell sand processing die, why did you select 4140 grade steel. Humble cast iron is adequate for several reasons including machinability, thermal stability etc.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[WKTaylor]

Familiar with Nitriding 4140... but not carburizing... carbon is too high?

Unfamiliar with any other way to selectively harden 4140 surface without distortion.

Regards, Wil Taylor

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[EdStainless]

We have customers that carbo-nitride 4140, you want to push the surface C up to about 0.60%, but...
I am with our friend, why use 4140 for this?
We used to make these from resin (epoxy) coated wood, and they made >10,000 cores.
Hardness is one way to resist erosion, coating with something flexible (rubber, urethane) would also do it.

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P.E. Metallurgy, Plymouth Tube

 

[metengr]

arunmrao nailed it.

 

[MetallurgistA]

dear all thanks for your answers. is cheaper in comparison with hot-working steels. and in our factory wee need to produce our die on ourselves in our factory which is not high-tech. any way, machniability,weldability, surface hardening, fatigue resistanc, wear resistance, low cost, good heat transfer and ability to be surface-hardened are important to select suitable die. so, according to this parameters which die do you dear all suggest me?????? please suggest me, low cost is very important.
based on ASM vol. 4 i think Carbonitriding is ok with 4140, is not it ?

best