Caring Iron: The Mysterious Attraction of Carbon in Soft Steel＾＾；

There are two types of Japanese knives, Honyaki (single steel or full steel, as it’s sometimes called) and Kasumi (clad, as it’s also referred to). Kasumi knives are made by layering soft iron (with very low carbon content) and steel (iron with carbon) to create the blade.

I’ve been pondering the differences in sharpness between Honyaki and Kasumi, as well as the impact of hammering on the steel molecules. However, I recently learned about other factors that affect the sharpness of Honyaki and Kasumi knives.

Just like in many other situations, things tend to flow from a higher place to a lower place. In this context, it’s the migration of carbon from high carbon to low carbon. Rather than reaching a temperature that is too high and then de-carbonizing, it’s the idea that the soft iron absorbs carbon. I’m not entirely sure about the specific conditions that lead to this, but it’s a fascinating concept.

However, this is just a small part of the puzzle. This is merely a diary entry for my learning journey. I’m still trying to figure out the specific circumstances under which this phenomenon occurs.

hibishugyo

2007-05-11