QT heat treated high carbon hot rolled steel sheet, high carbon cold rolled steel sheet, QT heat treated high carbon cold rolled steel sheet, and manufacturing methods thereof

A QT heat treated high carbon hot rolled steel sheet, comprising:

• in weight %, C:
• 1.0 to 1.4%, Si:
• 0.1 to 0.4%, Mn:
• 0.1 to 0.8%, Cr:
• 0.3 to 11%, W:
• 0.05 to 2.5%, P:
• 0.03% or less, S:
• 0.03% or less, Al:
• 0.02% or less, and a balance of Fe and other inevitable impurities,
• wherein a microstructure contains, in area %, carbide:
• 0.1 to 20% and the balance being tempered martensite,
• an average size of the carbide is 0.1 to 20 μm, and
• wherein the hot-rolled steel sheet has a wear reduction of 35 mg or less when a reheating temperature before OT is 800° C., a wear reduction of 27 mg or less when the reheating temperature before QT is 850° C., and a wear reduction of 25 mg or less when the reheating temperature before QT is 900° C.