Wiki-Aburayaki
One of the heat treating methods for Japanese knives, which uses oil to cool down the heated blade. Compared to quenching in water, the temperature decreases more gradually, which enables a relatively stable heat treatment without the risk of the blade cracking.
Related websites
White Steel#2 (Honyaki- Aburayaki) – KIREAJI
The Art of Making Japanese Knives: Detailed Process | KIREAJI