Effect of copper on the structure and antifriction properties of cast hypoeutectoid steel

Abstract

The structure, mechanical and tribotechnical properties of medium-carbon steel doped with 0…9 wt. % of copper with the 1% increment were investigated. During this study, the structural changes in the alloy with an increase of the copper amount were analyzed. Increase of the copper amount in the structure of medium-carbon steel leads to the gradually refinement of the ferrite grains and perlite components. In the samples doped with 9 wt. % of copper the tertiary cementite was found at the boundaries between ferrite grains and the colonies of lamellar perlite. The ϵ-Cu phase was revealed using X-ray diffraction of the cast steel with ∼ 3 wt. % of Cu. Further increase of the copper amount promotes the increase of ϵ-Cu volume fraction. The change in hardness and wear resistance with an increase in the copper amount in medium-carbon steels was detected. The samples doped with ∼ 6 wt. % of copper showed the maximum wear resistance at the non-fixed particles condition that corresponds to the hardness of material 240 HB.