Often favoured for components that are subjected to heavy loading, nitriding imparts a high surface hardness which promotes high resistance to wear, scuffing, galling and seizure. Nitriding increases fatigue strength by the development of surface compressive stresses. With a wide range of possible temperatures and case depths Pazmac is able to adjust different properties of treated parts to your custom requirements.
Here is a short summary of the benefits of gas nitriding:
Beyond the manual loading and unloading our gas nitride system runs with minimal supervision helping maintain low operating costs. As gas nitriding keeps your parts dimensionally stable, little or no post heat treat operations are required. It is considered low-cost compared with other case applications.
Pazmac processes a control coupon with each load. The coupons are catalogued and stored on site. Upon request the coupons are available for testing by either Pazmac or the customers approved lab. Each load is shipped with a detailed time-temperature chart and certificate of conformance.
Pazmac’s gas nitride process provides well controlled case depths and consistent surface hardness as well as maintaining a white layer thicknes of 20u or less.
Gas nitriding is a stable process which eliminates thermal shock during the heating and cooling stages. This also provides a dimensionally stable part with low distortion due to the reduced stresses imposed on the base material. The zero to minimal distortion experienced on parts enables precise dimensional control.
Surface Hardness and Case Depth
Parts can achieve a surface hardness up to the mid 60’s HRC with tightly controllable case depths of 0.002-0.030”
Pazmac’s gas nitride system is capable of loading parts up to 96” in length and 37” in diameter. Small parts can be process in large batch sizes.
Pazmac’s gas nitride system is environmentally safe and meets all current environmental standards
The gas nitride process requires a clean environment to achieve best results, the benefit to the end user is clean and residue free parts, ready for immediate use
Parts processed in Pazmac’s gas nitride furnace can also be provided with a superior corrosion resistant coating using the Nitreg-C option
Best Use Applications
In applications that require improved fatigue strength and precision, such as in extrusion screws and precision gears, gas nitriding is most appropriate. Highly-stressed machine components and low-alloy steels also benefit from the durability attained with this process. Low-carbon steel tools may corrode sooner than expected without this case application. Automotive parts such as crankshafts, valve parts and springs can maintain a level of malleability that prevents cracking under extreme conditions. Due to its enhanced corrosion resistance and anti-galling properties, it is a primary process used in aircraft components, from pistons, rods, and spacers to shaft pins, nuts and bolts.
Liquid Nitriding vs. Gas Nitriding
Gas nitriding disperses gas to the metal via heat in a furnace or sealed atmosphere. Liquid nitriding uses a cyanide salt mixture in a bath. The heat requirements for liquid are lower than for the gas technique, and the hardened compound on the surface of the component is thicker. The operation is simple and the processing time is faster than the gas-based method, but the salts left over are toxic. The gas-based process has easier disposal methods of the nitriding agent.