Decarburization ..observed in hardening & Tempering

[aansssa]

Hi,to all of you,
Plz suggest to me how to controlled decarb in hardening tempering process.
how much decarb should be.

 

[tbuelna]

A good start would be using the proper atmosphere when heating the steel. You can also remove the decarburized outer surfaces if you find it too difficult to control during heat treat. As for the acceptable level of decarburization in your part, that is entirely up to you. Section 3.5.1 of AMS 2759/1 provides guidance for accept/reject criteria of decarburization in heat treated alloy steels with a TS below 220ksi.

 

[aansssa]

thanks sir for ur reply.1% is acceptable from section thickness.
and heat treatment done in gas fire contineouse furnace atmosphere is a big issue for reduce decarbourization.
and second thing is we have tk soaking time in eace trey 25 min and wt is part 700gm
is soaking more.
is pc burn in heat treatment
decarb can be also accure after forging.
and what effect in after machining if decarb observed

 

[metman]

and what effect in after machining if decarb observed

Apparently the parts are machined after heat treatment. If so, this should remove any decarb, depending of course on how much material is removed during machining but any un-machined portions of the forging would still have decarb.

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