What is difference between hardness and hardenability?

Hello Pals,

Hardness and hardenability, there is always confusion about these terms. Difference is one property of steel and other is ability of steel to achieve hardness property to certain depth.   

 

Difference between Hardness & Hardenability:

Simplest explanation for difference

 

Hardness – Measure of property
Hardenability- Ability to be deep hardened

 

What Difference?

Hardness:

Measure of resistance of material to deformation or to surface indentation. It is function of stress required to produce specific deformation. Hardness is a property that represents an effect of complex elastic and plastic stress fields set up in the material being tested. To Express hardness quantitatively there are different hardness scale. Different hardness test methods like Brinell, Rockwell, Vickers etc. are used to measure hardness.  

Hardenability:

 

Relative ability of material to achieve targeted hardness to certain depth e.g. alloy steel can be hardened or can achieve specific hardness at greater depth than plain carbon steel. Hardenability is measurement of depth from surface where specific hardness is achieved. Jominy end quench test is commonly used to test hardenability. This hardenability test uses Rockwell C scale for hardness evaluation.  

So the main difference between hardness and hardenability one is actual property other is measure of ability.