Effect of Ni, Mn, V, and Al on Toughness of Blade Steels

In modern high carbon steels, Mn alloying binds S, and usually Al or V precipitates prevent grain growth. Primitive steels do not contain these alloying elements, but they may contain Ni, obtained from iron meteorites. Totally unalloyed carbon steel (0.7C–0.02Mn–0.01S–0.01P) and Ni steel (0.7C–4Ni–0.03Mn–0.01S–0.01P) were made in a laboratory foundry and their properties were compared with modern high carbon steels in a bladesmith forge. The unalloyed carbon steel suffered grain growth. Therefore, after low temperature tempering it had exceptional poor toughness, but after higher 250°C tempering it was as tough as equally hard (57 HRC) modern fine grained carbon steel. The Ni alloying increased toughness in the case of low temperature tempering, but it also reduced attainable hardness. The studied Ni steel was equal to modern carbon steels up to 62 HRC. The study showed that Mn, Al, or V alloying is not mandatory for the best quality blade steels.