En24 is equivalent to SAE 4340 material.We can nitride and achieve around HRC55 to a case depth of 0.5 mm depth. Liquid nitriding will give you only shallow depth
But all these are possible in this material only in gas nitriding. It is a prolonged process upto about 60 hrs. in a sealed furnace by feeding ammonia gas and cracking it at 530deg.C. Prior to that the job should be hardened at 840 deg C,oil/isothermal quenched and tempered at 560 deg C. this will ensure core toughness. Gas nitriding is post grinding process and the growth factor has to be considered.
Gopalan
Metallurgist / India
E mail gopalan_arunachalam@yahoo.com
Liquid Nitriding on EN24 Material
