Ferriscope? 4

[Hercules28]

Dear all,

Has anybody used a ferriscope to measure the ferrite percent in duplex and super duplex stainless steels?

What are the pitfalls with its use?
Any recommended manufacturers?

Thanks,

Herc

 

[stanweld]

We have used the Fisher Ferritescope in the past and will be using it in the future. Google Fisher Ferritescope for more details.

 

[jwhit]

We just got one, it seems to work quite well. The only drawback, and it is common with any of the austenitics and duplex stainless is that the ferrite content of the sample isn't necessarily homogeneous, tending to be higher in the thick sections and lower in thin. That isn't a fault of the instrument though, more related to inconsistent cooling in the sections of complex shapes. Wrought materials are probably more uniform than cast.

 

[EdStainless]

There are a few devices that do this, each is a different design and they are not exactly equivalent.
The Fisher units are reliable, but not field robust. You have to handle them carefully.
I have found them very reliable.
Surface condition of the welds can have some impact. Very uneven welds may give incorrect results.

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Plymouth Tube

 

[weldtek]

We've been using a Fischer Ferritescope for the past 8 years and it's been a great help to us. A word of caution though, the probe tip is sensitive to heat and can be easily ruined by testing welds that have not cooled adequately. My guys have been instructed to allow welds to cool sufficiently so that one can place their hand on the area to be tested. New probes are expensive.

 

[Guest102023]

Fischer Ferritscope is my instrument of choice.

However, no instrument can do anything about macro-inhomogeneity of any sample.