Abstract: In order to study the role of vanadium in hypereutectoid tool steels, microstructure observation, mechanical property test, heat treatment test and abrasive wear test were used to compare and analyze the microstructure and properties of the two hypereutectoid tool steels with and without vanadium after hot rolling and heat treatment. The results show that under the same hot rolling process condition, fine VC particles with a diameter of not more than 10 nm are precipitated in the V-containing steel, the colony size of the pearlite are smaller and with finer lamellar spacing, the yield strength, tensile strength and hardness are 116 MPa, 179 MPa and 3.2 HRC higher than those of the V-free steel, respectively. When tempered at temperatures below 550 ℃, with the increase of tempering temperature, the hardness of the two tested steels gradually decreases and the wear rate gradually increases. Under the same heat treatment process conditions, the hardness of V-containing steel is higher, the wear rate is smaller, and the tempering resistance is better. The tempered hardness at 450 ℃ still reaches more than 53 HRC, and the wear rate is less than 23 mg·km^-1. Tempering at 500 ℃ is a turning point in the deterioration of wear resistance of the V-containing steel. When tempered at 500 ℃ and above, VC particles with a size of above 100 nm precipitate in the V-containing steel, resulting in a significant increase in wear rate and deterioration of wear resistance.

Key words: hypereutectoid tool steel, pearlite lamellar spacing, hardness, tempered martensite, wear rate