Hardenability

The end-quench after Jominy, also Jominy test (DIN EN ISO 642) is a method of testing of materials and used to test the hardenability of steel. Is determined is the highest attainable hardness during quench hardening ( hardening effect ) and the hardness curve in depth at a given cross section ( Einhärten ).

Course

A cylindrical steel sample of 100 millimeters in length and 25 millimeters in diameter is heated by the material-dependent normalizing to hardening temperature, then taken within 5 seconds from the furnace and quenched at the front side of the bottom at least 10 minutes long with a 20 ° C water jet.

Thereafter, the cylinder surface is opposite ground plan of between 0.4 and 0.5 millimeters. Starting from the edge of the end face is quenched progressively (1.5 - 3-5 - 09.07.11 - 13 - 15-20 - 25-30 - ... mm), the Rockwell hardness (HRC) or Vickers ( HV30 ) measured.

The values ​​obtained fall from a maximum at 1.5 millimeters, the farther you get away from the quenched end surface.