Influence of Cleanliness on Mechanical Property of 40CrNi2Mo Steel

40CrNi2Mo steels were prepared by vacuum arc remelting (VAR) and electroslag remelting (ESR). The cleanliness was evaluated and its effect on mechanical property of the two steels at different tempering temperature was investigated. The results show that because of cleanliness of the VAR steel is higher than that of the ESR steel, the impact absorbing energy (−40°C) and percentage reduction of area of the former are higher than the latter, while there is little influence of cleanliness on hardness, tensile strength, yield strength, yield-to-tensile-strength ratio and strain hardening exponent of the two steels.