Testing of the through-hardenability of steel

 
The end quench test, also Jominy test named, is used for determination of the hardenability of steel. The samples used for the test execution have a length from 100 mm and a diameter from 25 mm. Over a time of 20 minutes the sample gets heated on a temperature which is suitable for the material. It must be held on this temperature for 30 minutes. Scale build-up as well as carburization or decarburization of the test piece is to avoid. In the following the sample must be quenched within 5 seconds. The quenching is made in a testing set where a jet of water hits on the sample face. After the cooling, quenching time under the jet of water at least 10 minutes, the hardness through HRc measuring is to determine. On the sample becomes, staggered put up at 180°, two testing area grinded (ca. 0,4 - 0,5 mm deep) in longitudinal direction. The HRc testing takes place in fixed distances. In the general the first distances related to the face are 1,5 - 3 - 5 - 7 - 9 - 11 - 13 - 15 mm. Afterwards all 5 mm becomes checked. The results can get registered in a diagram. The effective hardening depth is then readable directly. Nearer details about the experimental setup and general conditions to the test are written in the specification EN ISO 642.

In the following some material examples are listed. Represented are crystalline structure and the hardness checked by Vickers. The micrographs represents a approximate average value in the direct surroundings of the testing zone under considering of segregations.

1.7220 - 34 CrMo 4

1.7225 - 42 CrMo 4

1.7176 - 55 Cr 3

1.7147 - 20 MnCr 5

1.7160 - 16 MnCrB 5

1.7002 - 46 Cr 1

1.5752 - 14 NiCr 14

1.6587 - 17 CrNiMo 6

1.7030 - 28 Cr 4

1.7168 - 18 MnCrB 5

1.6541 - 23 MnNiCrMo 5-2

 

 

back to examinations