Heat treat interpretation 4

[daewoo]

I have a part that requires the following treatment:

690 + 100 HV 10
Eht 550 HV 1 = 0.8mm + 0.4mm

What is the correct way to interpret the above?

 

[CoryPad]

690 + 100 HV 10 means that the surface hardness must be between 690 and 790 when tested using a Vickers indenter and a 10 kg force.

Eht 550 HV 1 means that the part must be hardened to at least 550 HV 1 (Vickers indenter, 1 kg force) at a depth of 0.8 mm minimum and 1.2 mm maximum. This is a designation from DIN 50190.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[TVP]

Just to add one more detail, Eht means case hardening by carburizing, while Nht means nitriding and Rht means induction hardening.