Compare the indicative cooling severity of common quench media and evaluate how agitation changes the preliminary quench-severity factor.
The Grossmann quench severity factor, commonly represented by H, is an empirical parameter used in steel hardenability analysis. Higher H values represent more severe heat extraction at the steel surface.
A simplified relative comparison between two media can be expressed as:
For example, a result of 2.0 means the selected effective H value is approximately twice the comparison value within this simplified reference model.
Agitation changes the fluid flow around the hot steel surface. Increased circulation can remove vapor or heated fluid from the surface more rapidly, generally increasing heat-transfer effectiveness.
The practical effect depends on the medium, agitation method, workpiece geometry, tank design and fluid condition.
Quench severity is one factor affecting the cooling rate experienced by steel during hardening. A more severe quench can increase the ability to cool a section rapidly enough to form martensite, depending on the steel's hardenability and the section size.
However, increasing quench severity does not automatically mean better results. Excessively severe cooling can increase the risk of distortion, residual stress and cracking in susceptible components.
The temperature of the quenching medium can influence heat-transfer behavior and therefore the actual cooling curve. A cold fluid and a hot fluid do not necessarily produce identical cooling behavior.
This calculator displays the temperature difference between the steel and the quench medium as contextual information. It does not attempt to calculate a complete transient cooling curve from temperature alone.
What does quench severity mean?
It describes the relative ability of a quenching system to extract heat from hot steel. Higher severity generally corresponds to faster surface cooling.
What is the Grossmann H factor?
H is an empirical quench-severity parameter used in hardenability analysis to compare heat-transfer conditions at the steel surface.
Is water more severe than oil?
Generally, yes. Water-based quenching is commonly more severe than ordinary oil quenching, although actual severity depends on the specific process conditions.
Does agitation make oil quenching more severe?
Generally, yes. Agitation can improve heat transfer and increase the effective severity compared with still oil.
Is brine always the best quenching medium?
No. Greater quench severity is not automatically desirable. Excessive cooling severity can increase distortion and cracking risks in susceptible components.
Does this calculator predict final steel hardness?
No. Hardness depends on steel composition, hardenability, section size, cooling history and other heat-treatment variables.
Can this tool replace a cooling-curve test?
No. Actual quench-system performance should be evaluated using appropriate process measurements and validated heat-treatment procedures.