HRC=30+(50x%C)

[limct]

How does this formula HRC=30+(50x%C) relate to the case hardness of almost reaching HRC58 on the quenched C1045 steel bar of 1 inch diameter?

Best regards,
ct

 

[mcguire]

The hardness of untempered martensite in carbon steel is proportional to the carbon content by that formula. If you do a microhardness traverse of the case to the core you can approximate the carbon content by the hardness. In your example the carbon content of the case averages 0.88% carbon over the depth of the hardness impression.