The materials microstructure and not its hardness determines abrasive resistance wear characteristics. CASTEL has a dual metallurgical structure consisting of very hard carbides embedded in a soft matrix. Quenched & Tempered Steels have a predominately single metallurgical structure.
Abrasion resistance is not related to hardness as hardness values only become relevant when comparisons are made within a family of steels.
Chemical composition, microstructure & bulk hardness influence abrasion resistance.
Abrasion resistance is not apparent in a hardness test but in a actual wear test such as ASTM G65