Using dye to detect stress cracks in 5160 steel.

[Scott Miller]

I've heard you can coat metal with a dye solution and be able to see minute cracks under a black light. Anyone know how this is done and what kindbof dye is used?

 

[uxo2]

Magnaflux

 

[me2]

Yep. What he said. You will also need a good cleaner/degreaser, and a developing spray, also by Magnaflux. You can use Magnaflux's red dye, and won't need the black light. The developing spray is white, so you can see it pretty well.

 

[Danke42]

Magnets for steel.

The dye kits are aimed at non-ferrous materials.

 

[me2]

The full name for the process is dye penetrant testing. Dye penetrant will work for steel. It depends on how well you clean them.

If you want to do it yourself, reliability is lower, but cost is much lower. If you are going to use it for a critical application, have a lab do it. Also, if you have a lot of them, a lab could do high volume.