QPQ vs. Nitrotec (Gas Nitrocarburizing) 1

[toes112]

Besides the environmental differences, is there really any difference to the end product between these 2 surface treatment processes? Hardness, Aesthetics, Durability, Part Deformation would be key characteristics.

 

[CoryPad]

I think where you stated QPQ you meant salt bath ferritic nitrocarburizing (FNC). QPQ is a three-stage process that starts with the salt bath FNC, then has a mechanical polishing step, then a final immersion into another salt bath to oxidize the surface. QPQ has better corrosion resistance and lower roughness than gas FNC, and QPQ is black instead of silver/gray. Both treatments improve the surface hardness of ferrous metals. If your application requires the use of a lubricant, then the wear performance of these two treatments may differ. Otherwise, likely they will behave similarly.

 

[is2634]

In vision applications the QPQ will provide a less reflective flat black background enabling better image definition.

 

[mighoser]

Gas nitriding can develop much deeper cases but the risk of spalling of the hardened layer increases with case depth.