PARTIALLY CARBONITRIDING HEAT TREATED STAINLESS STEEL FERRULE AND MANUFACTURING METHOD THEREOF

摘要

This invention relates to a partially carbonitriding heat treated stainless steel ferrule, having a first region with a first hardness and a second region with a second hardness, wherein the first region includes a nitrogen layer having a nitrogen concentration higher than a carbon concentration, and a carbon layer formed under the nitrogen layer and having a carbon concentration higher than a nitrogen concentration, so that the first hardness is greater than the second hardness. Thereby, partial heat treatment is effective at preventing rotational torque of the region, except for the portion to be heat treated, from increasing due to the total hardening.

主权项

1. A partially carbonitriding heat treated stainless steel ferrule, having a first region with a first hardness and a second region with a second hardness, wherein the first region comprises:
a surface layer having a thickness of 0.005 to 0.1 μm and nitrogen and carbon concentrations higher than 1 wt % based on a total composition; a nitrogen layer formed under the surface layer and having a nitrogen concentration higher than a carbon concentration; and a carbon layer formed under the nitrogen layer and having a carbon concentration higher than a nitrogen concentration, wherein the first hardness is greater than the second hardness.