Knife Steel Nerds

There are many modifications to a straight high temperature austenitize for a given hold time followed by quenching. I am covering a few of them in this article.

Preheating

Preheating is performed to minimize size change, distortion, and cracking during heat treatment. Often a single preheating is recommended, but for some grades two preheating temperatures are recommended. For example, the Vanadis 4 Extra datasheet recommends a first preheat temperature of 600-650°C and a second of 850-900°C, such as in the following schematic [1]: read more

Carbide Volume

As covered in Part 1, carbide volume decreases with increasing temperature. As an example, here are micrographs showing carbides in a spray-form version of the original Vanadis 4 (non-Extra) [1]: read more

Update 7/6/2018: Since the writing of the original article I found some excellent micrographs that show austenitization very well and serve as a good supplement to the schematic diagrams. Go to the bottom of the article to see them. read more