No, there is no direct conversion between hardness and yield strength. While these two material properties are related, they measure different aspects of a material's behavior.
Hardness is a measure of a material's resistance to localized plastic deformation, often determined by indentation or scratch tests. Yield strength, on the other hand, is the stress at which a material begins to deform plastically. While there may be some correlation between the two properties, they cannot be directly converted without considering other factors.
However, there is a formula for the relation between the ultimate tensile strength and hardness, which provides an approximation of the ultimate tensile strength of a material based on its Brinell hardness: Tensile strength in MPa = 3.2 * Brinell hardness. This formula does not give information about yield strength.