What makes a good carbide former?

[Storm W]

this is mostly a question for Larrin . I was looking through a list of melting temps for different metals and noticed how high the melting point for niobium and wondered if that is part of why the carbides don't go into solution at austenuzing temps. That also made me wonder if there are any other interesting carbide formers that could be tried and will any alloy form carbides or are they special.

 

[DevinT]

Niobium, vanadium, tungsten, molybdenum, chromium, iron, and sometimes titanium. These are the main ones. They dissolve at different temperatures and have different hardnesses.

Hoss

 

[DevinT]

There are also lots of mixed carbides like chromium rich iron carbides, tungsten-molybdenum carbides etc. Larrin will know. 52100 for example, cuts longer than 1095 most likely because the carbides are chromium rich iron carbides.

Hoss

 

[Larrin]

this is mostly a question for Larrin . I was looking through a list of melting temps for different metals and noticed how high the melting point for niobium and wondered if that is part of why the carbides don't go into solution at austenuzing temps. That also made me wonder if there are any other interesting carbide formers that could be tried and will any alloy form carbides or are they special.

The melting temps of the individual metals doesn't matter that much because the additions are made as a "ferroalloy" such as ferrochromium, ferroniobium, etc. Molybdenum is commonly added as an oxide. The melting temperature of the ferroalloy is lower and mixes more readily in the liquid iron. Most/all of the potential carbide formers have been tried, including some that aren't used much such as Ta, Zr, or Hf.