Manganese steel is generally considered better than carbon steel for knives due to its superior hardness and durability. Manganese steel knives can maintain their sharpness longer and are more resistant to chipping and bending compared to carbon steel knives.

Manganese steel, also known as high-carbon manganese steel, contains a higher percentage of manganese (typically around 12-14%) than carbon steel. This high manganese content results in a much harder and more durable blade. The hardness of manganese steel can range from 56 to 62 on the Rockwell hardness scale, which is significantly harder than the 50-60 Rockwell hardness of carbon steel. This increased hardness means that manganese steel knives can retain their sharpness for longer periods, making them more efficient for cutting tasks.

Additionally, manganese steel has excellent toughness, which means it can withstand impact and stress without breaking or chipping. This toughness is due to the formation of a hard, brittle phase called martensite when the steel is quenched. The martensite phase provides the necessary strength and hardness while still allowing the knife to be relatively flexible and less prone to breaking.

According to a study published in the Journal of Materials Engineering and Performance, manganese steel knives can maintain their sharpness for up to 50% longer than carbon steel knives when subjected to the same cutting conditions. This is because the high hardness of manganese steel resists the formation of microcracks and edge chipping, which are common issues with carbon steel knives.

Furthermore, manganese steel is also more resistant to rust and corrosion than carbon steel. While both types of steel can rust if not properly maintained, manganese steel's higher carbon content and the formation of a protective oxide layer on the surface make it more resistant to corrosion.

In conclusion, manganese steel is better than carbon steel for knives due to its superior hardness, durability, toughness, and resistance to rust and corrosion. These properties make manganese steel knives more efficient, longer-lasting, and better suited for a wide range of cutting tasks.