Nital Etch Inspect

[CDHammis]

What is Nital Etch inspection for? When I read through several different specs, it appears that it is for checking for grind burns, does this mean that surfaces, where no grinding is done during manufacturing, do not need to be Nital Etch Inspected?

 

[TVP]

CDHammis,

Can you list some of the pertinent specs? I want to make sure that the nital etch in question specifically pertains to grinding defect observation, and not any general microstructure evaluation. In general, nital is applied to steel components in order to reveal martensite. When used properly, a nital etch will differentiate ferrite, tempered martensite, and untempered martensite, which is why it is specified for observing grinding burns.

 

[CDHammis]

The spec I am referring to is HPS3002. It seems very clear to me but I have had several people interpret it differently.

 

[TVP]

HPS3002 does not appear to be an consensus industry standard like SAE, ISO, AGMA, etc. Is this a proprietary specification from one of your customers?

 

[CoryPad]

I believe that is a Honeywell standard.

 

[CDHammis]

It is a Honeywell Spec.