Hardening On AISI 1015

Hardness in Carbon steels is afunction of carbon content.

The grade 1015 has a mean wt % of .15 Carbon.

This is insufficient to result in a high hardness developed by Heat treatment.

GAs carburizing is a process where carbon (from a gas containing carbon usually monoxide) is allowed to diffuse into the steel, raising its concentration in a layer by the surface to the point that it will be hardenable by quenching in liquid medium from above the critical temperature.

Then it will need to be tempered back to the desired hardness level.

Pack carburizing uses carbon rich materials to supply the carbon to diffuse into the steel.

These are called case hardening processes, as the hardness occurs only on the outer "case developed on the steel, not through hardening.

Your terminology is a bit confusing; "Grade" in common usage means "recipe" or chemical identity. HArdness is seldom described as a grade. Hardness Level or Hardness range or requirement might be a better description.

I am presuming you mean Rockwell A scale Which is properly called out as HRA.

If so, I'm confused as that scale is for thin harder materials than 1015 steel or it's developed case; Tungsten carbide is a typical material to be tested by HRA test.

milo

The steel you have mentioned, AISI 1015, this is a "low carbon steel" and not the material you would use by choice for through hardening. It is possible, as Milo has suggested, to increasing the carbon content of the surface layer of metal by case hardening. The depth of the hardened material is limited. Usually less than 1 millimetre skin thickness.

The hardness you require, Ra 81-83, is this meant to be HRa (Hardness Rockwell "a" scale) or a Ra surface finish?

Metal hardness testing Link: http://www.calce.umd.edu/general/Facilities/Hardness_ad_.htm

Ra surface finish Link: http://www.finishing.com/98/42.shtml

If it is hardness you want and not surface finish then a "Nitriding Process" will give you a hard shell but for a limited depth.

Please provide some clarification.

Yes, we need to obtain an hardness Rockwell A scale 81-83 on a depth of 1 mm.

We would like to treat parts in our workshop because of we have the right equpments but we didn't reach the required hardness.

I think the problem is to obtain the required hardness on that material, because we are able to heat treat other material like 18 Ni Cr Mo 5 obtaining very good results... but now we can't change material!

Of course you can heat treat 18NICRMO5: its an alloy designed for this case hardening application:

Chemical Composition

1015 has Nothing to Transform:

Heat Analysis

Wrong material!

Send parts to outside heat treater for case hardening is possible, they will use sophisticated carburizing/.carbonitriding process. ordinary shop methods won't get it done for you.

milo

milo