heat treatment query

[Ivsy]

Righteo have some results that were handed me for the testing of some .22% carbon mild steel and 1.0% carbon tool steel.

Now mild steel before heat treatment and tempering was 84HRB and afterwards 38HRC.

Tool steel before heat treatment and tempering was 67HRC and afterwards 97HRC.

Now my material science knowledge is sketchy at best but I have found information stating that mild steels with 0.1-0.3% carbon do not harden appeciably when quenched from above its upper critical temperate... but the results do not show this.

And aren't non heat treated tool steels generally somehwhere in the range of ~5HRC and after heat treatment end up somehwere around ~60HRC.

Or am I completely off mark here? Even a simple yes your right or a no your an idiot answer will do I just need some clarification. I just don't trust the results provided are correct.....

thaks in advance

 

[unclesyd]

Check the weights used and run a couple of standards on you hardness tester.
You hardness numbers are way, way off.

 

[arunmrao]

Get your equipment calibrated before testing. Results are misleading. who provided you the data?

Low carbon steel does not harden ,it can be case hardened only. Tool steels in annealed condition do not have such low hardnesses . Please recheck .

 

[TVP]

38 HRC is achievable with a 0.22% C steel that also contains ~ 1.0% Mn and 0.003% B. The grade is called 10B21 according to SAE J403, ASTM F 2282, etc.