Gas Nitriding Gears

Gas Nitriding for Gear Heat Treatment

All of our gas nitriding cycles are ran in one of our batch-type retort furnaces for optimum process and lot control.  All ThermTech furnaces are AMS 2750 compliant, with our largest furnace capable of performing the gas nitriding cycle has a working dimension of 30” DIA X 78” Long.  We run a shallow case depth load (0.003”) every night with next day turnaround for the convenience of our customers.  We gas nitride for deeper case depths on a regular basis.

The process of case hardening by gas nitriding is performed by heating previously hardened parts in a controlled atmosphere for a length of time commensurate with the case depth requirement.  Selective gas nitriding is possible through the application of nitride stop-off paints; after nitriding we hand-blast to remove the excess nitride stop-off paint using aluminum-oxide blast media.  The Gas Nitriding process occurs at relatively low temperatures and does not involve a quench; as a result heat-treat distortion is normally a non-issue.

ThermTech offers gas nitriding to case-harden gears made from previously hardened alloy steels, and are processed in a finished machine or near-finished machined state.  We also often recommend the gas nitriding process to case-harden gears where heat-treat distortion is of concern due to tight dimensional tolerances.  Nitrided surfaces also slightly gain in corrosion resistance.

Some of the gas nitriding processes we offer for previously hardened materials are:

  • Gas Nitriding of 4140
  • Gas Nitriding of S-7
  • Gas Nitriding of H-13
  • Gas Nitriding of P-20
  • Gas Nitriding of Nitralloy 135M

When distortion is not a major concern, we also offer Carburizing and Carbonitriding processes. We also offer Blasting as a secondary operation to improve part cleanliness.

Contact a sales representative today to discuss how gas nitriding can benefit your gear products!