The authoritative public forum
  for Metal Finishing since 1989
-----

What happens in salt bath nitriding if temperature exceeds 580 C?

My purpose is to get more case depth in salt bath nitriding. And I want to try temperature of 620 C. But Salt manufacturers don't suggest temperature above 580. I want to know what happens in the salt bath (what unneeded compounds are formed and what action other than nitriding occurs to parts) in case I try higher temperature. I want to know this so that I don't end up getting my bath/components damaged.

Maulik Savalia
shop employee - Rajkot, Gujarat, India
April 7, 2010

---

First of two simultaneous responses --

The same salt manufacturers have the answer. Ask them.

Guillermo Marrufo
Monterrey, NL, Mexico
April 8, 2010

---

Second of two simultaneous responses -- April 9, 2010

Dear Maulik Savalia,

In the salt bath Nitriding, the case Depth is depends on the Base material composition.

If, you base material is low carbon with low alloy, you will get higher the depth and lower the surface hardness.
If,you base material is High carbon with high alloy, you will get lower the depth and Higher the surface hardness.

Once Surface is reacted with Maximum Nitrides, again the surface will not allow inside nitrades.Because the surface will get saturated.

Case depth is depends on alloy.

If, your increasing the salt bath temperature you may get the slightly higher hardness, in the same your bath will get contaminated, like cyanide may increase and sludge formation will be more, etc.......

otherwise go for a two stage Gas nitriding method for higher case depth.

Kannan Boopathi
- Salem, Tamil Nadu, India

The same salt manufacturers have the answer. Ask them.

Guillermo Marrufo
Monterrey, NL, Mexico
April 9, 2010